I can't say I remember all the upgrades but things like 9.9K blue orbs for uncapped spawn limit or just about any economical upgrade that has a notable effect, leading up to big breakthroughs
If it's taking like 10 runs for a single upgrade (and several of them like that), that's generally too much-
Leading up to Elites, getting the Elite multiplier, Dasher chips leading up to double damage, early Elite chips between like the 10 and 33 mark etc - can't quite go back and look because once you've completed a run the save becomes void
I have no issue with it feeling rare and needing to work for it, just feel the progression for a few key points like those could do with being smoothed out a bit, rather than hitting a flat wall and flattening everything else after you clear it - the high (sometimes only of fast progression, not even being stronger in the level itself) is less than the aggravation of beating your head against it over and over until you pass it, in this case