An experience I had with a seller.

OP, I resonate with your frustration but understand the replies below, too. @mulveling has a nice take.

Here's where I resonate -- this is a hobby; part of the hobby is buying and selling, and part is the joy and interest involved. I've had really nice exchanges while selling, where the other person and I "connected" as two people who both love the hobby. In other cases, it was more like buying a pack of gum at a gas station.

The brusqueness you experienced is something to shake off. If the seller has an extensive history of sales, then they have dealt with a lot of annoying types of people. Your comment is one that I would have welcomed, because I value accuracy and *hate* to think I'm misleading people. But I don't sell a lot of stuff and so I haven't dealt with a lot of tire kickers.

My approach to seeing a mistake in an ad is something like, "I'll offer you X less than your asking price because your ad is incorrect about Y." This formulation directly connects the correction with a price-adjustment. Kind of forces the seller to either fess up and lower the price or shut me down. If they shut me down, we're done. I've had my say and resolved the question, "Should I buy from this seller?"

I tell my kids that some people are in need of a tune up, like the car. Seems to take the sting away in a relatively benign way. 

I'm not a huge buyer or seller for that matter, however if you're going to sell something, then at least be honest about it.  Marking something as a 9 or 10 that's 10+ years old or older to me is not right.  I'd say it's an 8 for age only followed by there are no marks or blemishes to be seen.  Especially when something is found to be definitely incorrect.  The seller should own up to that and expect the price to be adjusted accordingly.  I'm not sure I'd do any business with that seller based on his response to the facts no matter what his history.  How would you feel if you bought the piece, then afterwards found out that it was notably older than advertised ?  Yes, understanding the ratings can be somewhat relative, however let's be honest about the age and condition !  

Sounds likw the boy's having a bad hair day or he's just fos.

@liquidsound      Spot On!    Sounds like a simple solution telling the truth. The problem exits with many sellers’ integrity level. A personal example involved an Octave preamp. The dealer listed 9/10 on a store demo. I politely asked if the store demo had ever left the showroom and had been out on loan along with the usual cosmetics, age, original packing etc. The seller rudely stated if you want something perfect purchase new. This type of attitude prevails with many sellers of used gear. Don’t rate a component 9/10 or 10/10 if it’s not cosmetically perfect, can verify product history and has all original packaging intact.