Getting everything in ME2 means you gotta pretty much do everything!

You do not need to buy everything though. Unless you really struggle with the unlocking/hacking minigames, you do not need the bypass/hacking upgrades. Not buying these hacking upgrades will save you a good chunk of change.

Pro-tip: you can sometimes double-hack terminals, data pads, and whatnot by mashing the interact button after a successful hack. You can get double the amount credits this way from the hack this way.

Also: the key upgrades are the second and third upgrades; these upgrades will unlock the special upgrades for weapons and armor upgrades or whatever.

The DLC stuff added to stores are very inexpensive. Generally the extra bonuses are too small to be of much use early as you level up. There may be some exceptions for weapon damage + headshot damage if you are on Insanity and trying to one-shot kill with the Mantis.

Also, prioritize only the stuff you need, do not try to buy everything right away as you do not need everything right away. for example, ignore the fish and ship models since they are useless. Purchase them at the end of the game if you want them. If you are a Soldier, you do not need SMG damage (Squadmates suck with SMGs until the Tempest anyway). Caster classes can ignore most weapon upgrades until later. You may want sniper rifle damage upgrades for sniper squaddies or Soldier/Infiltrator Shepard, but otherwise you can ignore them until later.

The amount of credits you get now from an import are about the same as it was originally, so you have more than enough to get everything you need.

Also do not forget that you can a discount from every store except the star charts on Illium, which are very cheap. You will need to complete Grunt's loyalty mission to get the discount from Fortack's store on Tuchanka. Talk to Fortack after completing the mission to get the discount.

I am having trouble understanding points 1 and 2. You do not need to do that much exploration in the game. Most non-N7 missions do not require you to travel out of system (which takes fuel). Probes are cheap. Fuel is also actually fairly cheap. If you purposely do not recruit certain members or complete certain loyalty missions or whatever, then yes that means fewer credits. You will also not get the upgrades available on those missions. I do not see the issue as this should be expected. You choose not to do things that would give you more credits, you are left with fewer credits to buy things.

Regarding the Kestrel armor set: unless you want to add a little extra weapon damage or melee damage, avoid buying the armor pieces. Even the extra weapon damage is debatable on how much difference it actually makes. The extra shield damage is certainly pointless.

Just because you want to buy everything, does not mean you should be able to buy everything. I think that is the debate here.

If you want to argue that the DLC should have been all research terminal upgrades, then that is an argument I can get behind. We could then discuss how much resources each upgrade should cost (I think they should be more). I never bothered with the Varren pits after my first-ever playthrough; not enough credits to even try to save-scum it.

Look, I have done playthroughs where I had the minimum eight squadmates (no Thane or Samara, which leaves either Tali or Grunt as my eighth). I did not even do all their loyalty missions. I only purchased the upgrades I needed. The second and third upgrades matter the most since they unlock the special upgrades. The rest of the upgrades are just a nice bonus.

So dare I ask how much the DLC guns are in ME3? And hey, I don't mind doing Arena, but that's not till at least halfway through the game! Unless you can access that now earlier in the game?

Base price to buy all previous-DLC weapons and armor from stores in ME2 LE is 118,500 credits without any store discounts.
The most expensive items are:
- Blood Dragon Armor: 15,000 credits with no discount
- Terminus Armor: 12,000 credits with no discount
- Geth Plasma Shotgun: 10,000 credits with no discount

Also relevant to the conversation I think is import bonuses. I think these are the bonuses:
- 200,000 credits for completing ME2 at least once before.
- 100,000 credits for importing a "rich" character
- max 50,000 credits for importing an ME1 character (dependent on import level)

So if you want to increase the starting credits for ME2, would that be a flat bonus (added to the ME2 completion bonus or "rich" bonus), or would it be a scaling bonus depending on the import level?
What would be the amount of credits that you would add as a flat bonus?
For a scaling bonus, what would be the min and max bonuses?

---

As for ME3, while you can grind the simulator for credits, it will take time. ME3 also has the issue where you are not just buying weapons, but buying weapon upgrades. Most weapons are capped at rank V for a first playthrough (currently you can cheat a bit with some rank V weapons that you "buy" rank VI on a first playthrough). For most weapons that can be found on missions, they will gain 3 ranks when you pick them up again in NG+. For weapons you buy, you have to buy all ranks. This can potentially double (or even triple?) their total original buy value.

You can earn 10,000 credits for a match in the arena (Gold prize). Assuming a modest 5 minutes per match (including breaks between rounds, time to load the match, plus buffer), that means you can earn 120,000 credits per hour.

So if you want to buy everything, you can grind waves in the arena. If you want to MAX everything, it will take at minimum two playthroughs. And even if you plan around it to max your buying potential, you will have to grind a lot of waves in the arena. That will take hours of grinding. I had managed to do it pre-Legendary Edition and it was a slog. I do not even want to know how long it will take now that I have to buy a bunch of stuff for a stupid amount of credits first. Not sure I ever want to do it. I have never used the Valiant in single player before. I may never use it until maybe 2-3 years from now.

Yeah I cannot say I am big fan of it...   quite a generic design

Yes, I'm that up... and I'll probably delete my account again whenever I'm done this round of talking about ME... saves me trying to remember who I "was" here and limits the number of different logins I have to keep in my head.  As I've gotten older, remembering such things has become more of an issue.  It also forces me to "cool off" and lower my blood pressure when I'm not tempting myself to keep tabs on everything going on the various forums I used to subscribe to for the various games I play... although with various devs no longer supporting forums, some of my old accounts have effectively deleted themselves over the years.  I honestly don't usually "rage quit" anything though.  It's a little frustrating when I feel I'm being misunderstood, but I generally honestly enjoy a good, civil debate... and I've certainly enjoyed conversing with you on many topics.