Has anyone sold over $35k worth of equipment over the net? How do you protect yourself?

This past May my wife and I took a long road trip vacation. We were tipping wait staff with cash and abut half way through the trip I was low on ones, five and tens, so  I stopped in a bank to break a couple of twenties. Even with the circumstances explained, I had to provide photo ID for the bank to copy. The reluctantly gave me $40.00 worth of small bills for 2 twenties. When I got home I talked to my banker about this. He said most banks will not break cash unless you have an account with them so they have recourse. He went on to say, that not a day goes by the local McDonalds doesn’t get burned with forged twenties, and I live in a community of 5,000. Point is, there is apparently a risk with every transaction made these days. I learned that carrying cash would have been useless had I needed it. It can’t be trusted.

I've sold cars that price and we met outside their bank and they went in and got a cashiers check. Pretty safe and no take-backs. 

A Bank Transfer takes minutes, if the Purchaser has the correct info in their possession when viewing the equipment and decides to purchase.

I usually arrange that my Wife is on Standby remotely, she is treating herself to a speciality Coffee or similar treat for herself, whilst I go off into the world of being a Purchaser of a used goods. My Wife will be the one who makes the Payment Transfer to the supplied Banking Details when all is agreed about the sale. 

By the time it takes to make a Coffee, the Transfer will usually be showing in the Vendors account as a cleared funds.

I don't know what can be more useful to an individual, to give them confidence,  when there is a concern being raised about not receiving a bona-fide, non-specious payment for their sale items. 

Additionally, the Buyer does not have to concern themselves about risks to payment methods that are alternative and may require bringing along valuables they are not comfortable with bringing.