How do you pay? Why?

Everyone should be aware of one issue with cashiers checks and non-USPS money orders. There have been instances of counterfeits used to pay for goods here on Audiogon. If it turns out that you as a seller get one, your bank will look to you to cover the balance, and expect you to go back to the buyer to recover your loss (cold day in ....). Your bank manager may make the funds available to you immediately at their discretion, they may or may not put a hold on other funds in your account, but ultimately, if the buyers bank or other issuing entity refuses to honor a money order or cashiers check, you will be on the hook for the $$. There is another also one other issue here. Unless I am mistaken, there are federal laws covering clearance times for personal checks and they max out in days, not weeks. So if the seller says 2 weeks to clear, either they are misinformed, their bank is hosing them to take advantage of the float, or they don't want to take the risk of being stuck for a $30 bank charge if the check does not clear (and that is probably a legitimate concern when dealing with a low feedback member).

AS far as paying the 3% vig to paypal, I hate to do it, and usually won't on major purchases. If the seller's price is fair, I will offer to pay full price and let them decide if THEY want the funds quickly enough as to cover the fee themselves.

One other point (I promise). There IS one advantage to paypal for a seller besides quick access to the funds; it cuts down on failed deals due to " (potential) buyer's remorse, where financial or other realities set in before they can get to the bank and p.o. I've had my share of "I changed my mind" emails after agreeing to a price and other terms. That is the one advantage of the Audiogon transactor.

I usually pay with a tellers check from my credit union, unless another form of payment is requested.

As for receiving funds, if it’s a USPS MO, I just go to the PO & cash it there. If cashing a bank draft, MO, personal check, etc, I go to that bank to cash it, but if no branches are in my area, I call the bank to make sure funds are available before I deposit in my account. I have had zero problems receiving payments.

I don’t like the idea of paypal, mostly because they are unregulated and can do what they want with your money.

As a seller I like PayPal for smaller items and USPS money order or cashier's check for pricier items (say $500 or more). My bank teller told me that even though funds would be available to me immediately from my deposit of a money order or cashier's check, there was the possibility that a few weeks down the road the check or money order could turn out to be a fake and then I'd be on the hook. I asked him about the cashier's check I was about to deposit. He took one look at the issuing check service and said it was a reliable one and this check was very likely good. I deposited it and had no problems. Again, buyer's feedback and communication with you as seller is critical.
As a buyer, I like to use PayPal too, it's far more convenient and I can do it immediately rather than wait in line at the bank or PO or both before work. If the fee is not covered by the seller, or amounts to more than about $15 though, I don't use PayPal. Paying a $15 fee is about my limit for convenience. Sometimes, sellers will pay or split the fee with you though, for mutual convenience. The service really does benefit both buyers and sellers even though PayPal funds do not clear into your bank account for 4-5 days. You can just wait to ship until the funds are in your bank account. But if the buyer has good feedback I go ahead and ship as soon as the payment has been made, esp if the purchase is for a relatively small amount.
I have been lucky on both ends, as buyer and seller, following these practices for over 6 yrs of trading on Audiogon, Head-Fi, and eBay. I am the MOST cautious dealing with eBay of course. The other two sites are for extreme hobbyists and I've never yet been burned by one of those lunatics (self included).

My post office won't cash in USPS money orders because they never have enough money on hand to do it. Then my bank holds them for 5 business days... So USPS money orders are no good for me anymore.

Don't confuse 'posting' time to your account vs actual clearing. Hence CCs and MOs post immediately, but you may find out a couple weeks later that it is counterfeit, leaving you holding the bag. It is, however, not typical to see counterfeit items like these, so in that regard it is 'safer'. I always ship upon receipt of a CC, but I am still taking a chance, although a small risk im my opinion.