i would wait until i recieved the amp and saw that it functions properly before i closed a dispute that was opened on pp. if for some reason there is something wrong with it (not saying that there will be), you would not be able to file a 2nd dispute/claim.
OP probably jumped the gun labeling seller as a scammer and also filing a claim. if seller would have maintained communication it would have been easily avoided. with as much scamming that goes on on this forum it is quite easy to jump the gun.
as for $65 not being a scam? are you for real? the amount of money/equipment involved has nothing to do with being scammed or not.