Most all of my audio purchased over the last 20 years has been local used equipment, so cash is called for then. Second would be on eBay, and then it's PayPal. Lastly, if I'm buying from a store, it's credit card, always (usually with something that will add a year to the warranty like an Amex card).
I was referring mainly to audio gear, and I finally posted my vote to my own thread--just depends. With the exception of check/money order, I use all of the above, depending on circumstances of purchase. I guess I just wanted to poll the "preferred" method of payment for the bulk of your audio acquisitions.
Really depends on where I am buying it from. In-person transaction via something like Craigslist? Cash only. eBay I generally use Paypal. Other places on the net I either use Paypal or my credit card directly depending on the site. I think in the last ~15 years I've written a total of three checks, and those three weren't because I had a choice.
Hifi component purchase, unless I am physically in a store, are 100% Paypal for my transactions. If I'm buying in a store, I typically use cash. Cash in had has yielded some nice discounts on stereo equipment. You know what they say....money talks and bull*** walks. In fact I just placed an order with Audio Classics this past Friday...they sent over a invoice via PayPal as requested.
I use mostly cash when purchasing gear on Craigslist. I've also used Venmo for Craigslist deals, but only as a seller. When I sell refurbished stuff it's usually to younger folks around my age who sometimes prefer apps to send money rather than carrying cash. It's worked well for me, and I can instantly see the funds transferred to my account.
Cash is king. I don't fool with ebay or paypal or anything but cash. I never buy anything unless I'm right in front of it with the dollars. This way I don't worry about shipping rules, fees or damage plus I have more bargaining power to negotiate. Sure I wait longer to get certain pieces I'm after but they do come and go eventually - every make/model I want comes around sooner or later. Plus I actually meet people in person which helps establish ongoing buy/sell/repair relationships.
I'm not selling stuff yet but when I do they will bring cash to my door. All sales will be final.
Credit card when buying from overseas. When buying locally over the internet I use either credit card or electronic funds transfer.
Otherwise use EFTPOS card (Electronic Funds Transfer Point Of Sale) since 99% of shops in NZ have it and I don't have to worry about carrying cash.
I'm assuming this to be a person to person sale, not from a retailer. With that in mind, online, mostly paypal unless someone requests a money order. In person its always cash.
Can't choose three in the poll. Cash for local sales; PayPal for online purchased via eBay, Audiogon, USAudioMart, etc.; debit card for retailer purchases.