I have to say the microtransactions issue in GT6 is a non-factor to me as well.
Mostly it's because I look at the game more as an encyclopedia and into simply just doing hot laps with modest cars and modest mods, which doesn't cost too much credits in the game overall. And I'm not in a rush to blow by all the different racing classes anyways, just mildly grinding and slowly progressing whenever I have time. Most likely I won't be racing online.
My garage so far has a couple of 86/FR-S/BRZ variations, a couple of AE86s, a Mazda Miata NA, a Honda Fit RS, a Nissan GT-R R35, a Lexus LFA 'Ring, as well as the Merc GT Vision and the free cars voucher with came with the game. I have next to zero credits because of the money pits that are my Fit and Miata lol. That said, I'm a happy camper so far.