Buyer Protection.... ?

I'm looking at buying a heavy and expensive (to me!) piece of equipment.

The item looks legit, seller seems nice, but it has a price tag of over 5K. There is no feedback anywhere and I'm trying to figure out what I can do to protect myself without irritating anyone.

Neither of us has done a large amount of buying/selling online.

Any suggestions?

I'm not sure Fed Ex will ship items of this weight, for what it's worth.