assuming the part you are looking at is expensive ?
I have bought and sold many many parts on another forum and bought a few parts on here and have always used personal checks or postal money orders and have never had an issue.
The forum I have sold a lot on I am a moderator on and my feedback is flawless , I have had people buy nearly $1500 worth of parts this way and boy I don't think I would do that but it goes back to feedback on a big purchase if the seller has none and you cant do it in person then I don't blame you.
I just bought a headlight on here $65 shipped I ok'ed use of a personal check with the seller and told him not to ship until it had cleared on his end , just got tracking numbers lol
I have seen a few bad deals over the years but for the most part car guys aren't looking to screw other forum members watch out for low post counts or negative feedback. I have seen a few cases where paypal screwed a seller based on mis information from the buyer so I have never accepted it.