Great amp, crashed and burned after 30 hours... Buyer protection?


Fairly new at this hobby, but worried about getting burned by not so  honest sellers. How does one ensure the seller is a "good person" and will accept responsibility for their sale? Not have the attitude that "it worked when I had it" too bad it doesn't work after a few hours...!!
I have a really good buddy that has been doing this for years and he was severely screwed by what looked to be a very good seller. What is  your recourse? Need some good ideas before I dive in??!!
Thank you all 
oldstyle
Did your buddy happen to deal with a Audiogon member or someone from another site?
It may be off-base to blame the seller 
given the sudden and catastrophic failure of the gear, it may be a crap build equipment issue.

i had three (3) sudden .... And mean unforcasted and SUDDEN .... Catastrophic failures on the $4k top-of-line AVR and blu-Ray player.
with the receiver , it was fine and next use two days later .... Kaboom! New motherboard replacement and gone for 5 weeks 
warranty coverage ... Okay....but. Something amiss. 11months later was an instant repeat. Good thing it had a three yr warranty 

the Bluray player ( a $1500 unit) crapped out catastrophically suddenly in mid-movie . It was 27 months old and three months out warranty so I was SOL with repair costs exceeding its FMV.

I sold the AVR and replaced the BR with a quality build Euro unit...and Euro / USA quality build separates 

the moral of the tale:

- the  expensive and shown-to-be-unreliable Chi-fi gear I had was crap build POS gear ...full stop

- mfg OEM warranty through a distributor matters. Too many have only a 1 year .... Caveat emptor. Most used gear won't have it and the bargain price reflects that.

- your seller may have sold used gear on a proper belief that it was out-of-warranty but all good ON DELIVERY with no knowledge of any issues. The risk is entirely yours 


I think I read that oldstyles buddy's techie found "counterfeit" parts, which led directly to the failure, therefor whomever repaired the first time is the culprit. Also it was the sellers attitude that set him (her) off. The techie said it was lucky it lasted the 30 hours, which smells of deception on the sellers part, why else would he lay down "attitude"?
I suppose the "recourse" is to buy new with warranty from a reputable dealer.
 Let the truth be stated. I think that audiogon, indirectly, plays a role in the loss of security rather then gains in security. In the old days, you could call a seller and talk to them about their gear. For me that was the best vetting one could do.  I always felt that I could gain an intuitive sense of the integrity of the seller based on discussion of their gear and their passion for the hobby. We can no longer do that. I feel that we are at a great loss in terms of security when these transactions may amount to many thousands of dollars of risk. I understand that audiogon is protecting its bottom line, but there must be someway to allow a phone conversation before a deal is finalized, or to allow reversal of a deal if subsequent phone conversations  are unsatisfactory. Audiogon… Put on your thinking caps and come up with something. Do the right thing!