Where's the best place to buy a used excavator?

[IamBruce_Driver]

I'm in the market for a used excavator and trying to figure out the best place to buy one without getting burned. I've looked at dealers, auctions, and private sellers, and each seems to have pros and cons.

For those who've bought used:

Are dealers worth the higher price?
Any good experiences with auctions or online marketplaces?
Red flags I should watch for when inspecting a machine?

Just looking for real-world advice before I pull the trigger.