Assuming I wanted all mods, armor, model ships, and powers, etc. Is there enough credits in one play-through to buy everything? In other words, is there a source of credits in the game that's renewable?
In my experience, no. I've collected about 600000 credits altogether, and the Spectre Requisitions weapons cost more than that. You'd need about twice that to buy everything, and I doubt i've missed half of all possible credits.