Experience purchasing a used high-end cartridge

I recently bought a used Benz Ruby 2 from Wayne's Audio through US Audio Mart.

He stated he sells a lot of cartridges, he had several for sale, and good feedback.  He was offering several vintage cartridges that he claimed have fewer than 50 hrs. use and he's marketing his own MC cartridge.  He offered me a return privilege and installed the cartridge on my tonearm armtube.  He also gave me credit for a used cartridge I sent him.

The cartridge was carefully packed and works fine.  I've not felt a need to have it inspected, and I'm not sure there is anyone near me that would inspect it.

One advantage of buying a lightly-used cartridge from a trusted source is that it may be broken-in enough that you can judge how it will actually sound at its best; you can't always do that with a new cartridge.

I've done it, but only from trusted sources.  Can you return it?  Are they a dealer or an individual? 

Another thing to consider is cost of retipping.  If there is something wrong with it, or it's worn, can you have it retipped and still come out way ahead of the cost of buying a new cart?  One of my used purchases was a Van den Hul Crimson XGW Stradivarius, which at the time were fairly inexpensive to have retipped by the manufacturer.  I paid less than half the price of a new cartridge and have not had any issues with it to date.

Yes, but be very careful who you purchase from.  3 new cartridges that I purchased at used prices: VDH Colibri Grand Cru, Koetsu Coralstone D, Aida Mammoth Gold MkII.  

There is another method and one used by myself.

I sought out a Cart' in need of repair, which was a model I had already agreed a rebuild design for with a Technician from a Third Party Service.

I discovered a donor Cart' at a steal and took the Punt on the purchase.

The Third Party Service evaluation made it known the Cart' was in prime condition to undergo a overhaul but was filthy.

The end product Cart' fully overhauled cost approx' 1/3 of the Donor Cart's new value, and performs much much more to my liking than the Donor Original Model with a few hundred hours usage on it. 

I would like to first, and foremost, express my appreciation again for all of the valuable insights and experiences shared by the A’gon community.

@willy-t and @drmuso your comments were incredibly on-target for me, since the cartridge I was considering was a Kleos from Wayne’s Audio listed on US Audio Mart. Wayne was very responsive to all my inquiries. Based on the advice received here I requested an inspection of the cartridge. Wayne replied this was the first time that anyone had requested inspection and was not willing to risk having his cartridge sent out for inspection--a position I can fully appreciate.

Despite the professional and responsive message exchange, I decided it wasn’t worth the risk. Instead, I found a great deal on an open-box Soundsmith Sussorro ES from a highly trusted online retailer that I buy from regularly. They even agreed to mount the cartridge for me on a new Nasotec Swing Headshell that has received glowing reviews.

As @big_greg and others have mentioned., the retipping cost factored into my decision. Soundsmith has I believe the industry’s lowest retipping costs at less than 20% of retail. My only worry now is that before I need the Sussorro retipped Peter may have sold the company to someone focused more on extracting the highest profits than on customer service.