It depends on the coin design. If there is a particular design I like very much I will seek out a proof example. Otherwise circulated is fine with me (and fine is the condition I prefer).
Wrong, the Mint made many proofs before 1936. But they weren't consistent. There were periods where they stopped making them. For example, there are proofs of dimes and other coins going back to the 1850s. But they didn't make proofs of the Mercury dimes at all until 1936.
I figured. I'll look some other time .... but "I think" it was then, which it wasn't. But I collect proof and non-proof coins (and tokens and other non-coins) going back a few years.
I collect both. I DO love proof coins, and have a bunch of proof sets going back to the 60's. I also love Coin Roll Hunting which is where the bulk of my my collection comes from. It's always great to find a proof in a coin roll. I search auctions for proof sets, and when I can find a lot of them and the price works out between $4 and $6 dollars a set, I pull the trigger. Getting harder and harder to find like that though. My extras I sell through the antique shop.