Should I consider a used flute?
As with any used item for sale, there could be different reasons why a person is parting with it.
The one which you should be concerned about is that there could be some serious flaws, or that bringing it back to shape wasn't worth it.
They could simply be strapped for cash, or have no more interest in playing, or they inherited it. This is where you should look.
Buying from the owner, you would have to take it to your repair technician to check and service. Buying from a dealer, you should expect it to be serviced and ready to play. Sometimes the owner might be unreasonable and the dealer very reasonable, but it could be the other way around. As with used cars, the best is to consult your repair technician before buying. If possible, bring it to them to check. Pictures don't tell you much. It could be nicely shined up, but unplayable.