Smallwares like sheetpans, bowls, forms and pans, etc are fine. As others have said, ingredient bins start to get pricey when you buy 5 or 6 of them, and used bins are fine
Stay away from used refrigeration Unless you are a refrigeration mechanic, don't bother with this stuff, it just ain't worth it. Walk-in cooler panels are another story--you can re-use them over and over again, but the guts--compressor and coil aren't worth it
Deck ovens are another matter, very few moving parts to break down, and the only thing that really wears out are the elements. It's usually a safe bet-but a bulky and heavy sucker to move around.
Sinks look fine--at the surface--but most health inspectors want to see a NSF inspection sticker on sinks now. They want to see smooth coved corners and no welds or tight corners for crud to get trapped in. The Chinese have cornered the market for pre-fab s/s stuff like sinks, shelving, and tables, and it is pretty good and very cheap.
Mixers and stuff like additional bowls and whips/dough hooks are a good bet. They are easily repaired, not cheaply, but easily repaired, and everyone has parts and knows how to replace seals/gaskets or gears in a Hobart.