[tlb]

Most people are reluctant to accept large personal checks for one-shot transactions. Most people selling cars on Craigslist won't just take a personal check, for instance. It depends a bit on how reputable you look. You can't write one as bail, or to get your car out of the impound lot.

[perl4ever]

Most people are reluctant to accept large certified checks or money orders, going back to at least the 90s, because of counterfeits.