My one and only was an aquabid betta. I got mine from bettaakapes and he did a great job. He arrived at the transhipper alright (I can't remember who I picked, either jennifer or linda on the list) and came to my house fine.
Basically what I suggest is first getting the tank ready. If you are giving him a 5 gallon, go ahead and start cycling it so it'll be ready for him.
Meanwhile, go through and check out aquabid for bettas you like and see who is breeding them. When you choose the one you want you can bid or you will sometimes have the option of 'buy now' (that's what I did, lol didn't want to lose mine)...When the auction is over, contact the breeder and work out the payment. (You'll want to have paypal for this, get it a few days in advanced just in case if you don't have it. Mine took a day to activate.) The breeder ships your fish along with like 100 other fish to the transhipper every 3 or so weeks, so yours might get shipped out that week or it could take 3 weeks before he gets shipped over. That shipping will cost you about 5 bucks since it's spread out among the other buyers.
Contact the transhipper you chose and tell him/her everything they need to know. The transhipper emails you when they get the fish and will keep the fish there for about a day or two before then shipping it to you. THIS is where shipping gets pricy, be it from an american breeder or a thailand breeder. It's overnight if you want a live arrival guarantee, and that will end up possibly being 30 or so dollars. You make sure you are ready and at the house when the mail comes so you can be there to sign for the package! :) Then...You have a fishy!!!! At that point, do the same thing you would do with a fish from a store...slowly acclimate them to their new tank.
My fish was clearly not a DOA nor did he tailbite(though he is a plakat so, lol!) but he was very pale when he arrived. Didn't take him long to brighten back up though when he got to explore his nice big tank!
The nice thing about buying on AB is of course you aren't supporting chain stores with bad practices :) and you are supporting people who are involved in taking GOOD care of bettas. It's a little pricier, but often times worth it. And of course you can get guaranteed good genetics if you want to breed! Now, just because of the price, I might not buy from AB unless I am buying multiple fish(like getting a sorority) simply because that way the shipping price is split between the bettas and it isn't so expensive for just a single fish.