When I started, I only pursued games I wanted, but I also bought plus cheap unknowns when I stumbled upon them. There weren't a whole lot of online TG reviews in the Nineties/early 2000's and I've never been into emulation; how was I to know which games were bad? TG games don't take up much space and I saw no reason not to blow $10 on Shadow of the Beast or Tailspin. I'd spent so many years drooling over pictures in TTI mailing and EMG that I wasn't about to let some text-only Turbolist review dictate my purchases.
The thought of collecting didn't occur to me until I had ten years and 80+ games under my belt. Inflating prices and the fact that I already had most of the rarities motivated me to make a checklist. Other than Dynastic Hero, I only paid $100+ for two games (Bonk 3 hu cib, Bonk 3 scd) and $50+ for a few more (Cotton, BS, Godzilla, Terraforming).
I would not have collected with prices like they are now. In 2010, I decided MC was out of my range and threw in the towel. I'm happy with my 99% set and I still buy PCE games a couple times a year, but I couldn't care less about condition and I'm happy to grab loose discs and hucards when I have the chance.
Id rather take 40 bucks and buy something like Gradius II, then to buy TV Sports Basketball, World Class Baseball, and China Warrior. I may end up with 3 more games, but it is 3 I will never play, so why buy them?
For me, the "bad" games are part of why I like the system. Other than the occasional RPG, sim, or strategy game, video games don't hold my attention like they used to and I rarely play single-player action games for more than half an hour. Because of this, I have almost as much fun playing Darkwing Duck as I do SMB3. The only TG games I never touch are the two football games, the boxing/kickboxing titles, and Falcon.