Test firing a firearm before purchase

[kidicarus13]

Not a chance if a NIB unfired firearm. There are places to rent most of the firearms that are up for sale.
I dont see why this is brought up (by the potential buyer) when the ability sell a firearm you dont want after shooting it is extremely easy.

The OP clearly states not an unfired firearm. And selling a firearm that you don't want because you find that it has failures after purchase causes me to lose money or reputation:
1. Know it fails, don't tell buyer, sell it, buyer unhappy (I wouldn't do)
2. Know it fails, tell buyer, buyer offers me a lot less $ if he still wants to buy it
3. Know it fails, spend $ to get it fixed

The buyer should have known what they were purchasing and been able to look for signs of weakness or failure.

You must have magical powers because I have never been able to look at a firearm and tell if it is going to misfire or not before I shoot it.

To quench everyone's curiosity, I have never asked to test fire a firearm prior to purchase but spending $2K on a used 1911 would have me a but anxious considering my previous track record with 1911s.