There have been a number of threads on this and bottom line is that many things can be counterfeited and payment can be stopped on cashier checks, bank drafts, etc. Wire transfers can be reversed. If it matters, I understand the cash/check business and have stopped and reversed things and was no big deal.
Most people are honest but some aren't and I'm not taking on the added risk of figuring out who's who, especially when it's an internet transaction and you'll never find the people again. My job is to deliver the product and the buyer's job is to deliver good, meaning negotiable funds.
When I sell something these days, first choice is cash. Second place is to open an account at a branch of the bank I deal with. Then we go into my branch and you do a cash transfer from your account to mine. The buyer removes the cash from his act and I deposit in mine.
Third place is to wait two days after you give me a cashier's check or bank draft. In the mix is the escrow acct at an attorney or postal money orders since they can be verified on the net.
Now, if you want to know the value of that $10,000, just try to borrow it from someone on the street and give them a cashiers check for the $$.