Stay away from the guys that don't use PayPal, they generally perform less efficiently than the ones who do.
Not on my end.
Not my end either. That's like saying most the folks here don't perform efficiently....When in reality they do.
Weird statement - payment is payment, by any agreed form. Paypal has rules, if you violate them, you pay a penalty. If you pay/receive payment for prohibited items, you are taking a risk, with selling - you may lose your item, and the payment.
For OP - descriptions have to accurate, and very clear. The seller that gets trouble is one that doesn't disclose a crack in the stock, a drill/tap that wasn't factory, or is selling "a pristine rifle" while complaining four threads away that the barrel is shot out...on the same forum.
Everything you post for sale will be analyzed, and searched for on other threads to see if you have a rep someplace else as a good or bad seller. You are on a public forum, it comes with the freedom to post on the web.
Not every member here has access to a Post Office everyday, so demanding immediate payment can limit your buyers. However, pretty much everyone can reach an agreement on the form of payment, and the time expectations for shipping, waiting for payment to arrive, waiting to clear the bank, etc.
Post a price for what you are selling, this isn't an auction site. If you are open to offers, at least set a base price, and then accept offers.
Life happens, just don't go silent for two weeks in the middle of a sale as either the seller or buyer, as most members will understand with quick note them on the problem you are facing.
Same with the sale, don't start a call-out thread (Billy-Bob is a liar and a cheat, don't deal with him) unless you have all of your ducks 100% in a row. 99.99999% of the members are upstanding people, and have no intention of screwing another member over. Sometimes, life happens for them as well, be patient.