I've used Auction Arms several times, all of them I considered to be good transactions. I've purchased firearms, ammo, and accessories. I follow these rules when I'm considering buying:
1) Set a firm price BEFORE I bid that I won't exceed.
2) Figure out what I could buy the item for locally. When you add $25 for shipping and another $25 for FFL transfer, it may not be a great deal after all.
3) If there is not a picture, I don't buy, regardless of the price. Always remember, BUYER BEWARE!!
4) If it's a reserve auction, I sometimes shoot the seller an email before bidding. Over half of them tell you the reserve. Then I decide to bid or not. The bonus with this is that if you contacted them and it doesn't sell but you have the high bid that is close to the reserve, they might just sell it to you. I've had this happen several times on Ebay.
5) Check the sellers feedback. No history, no bids. I don't want to deal with amatures.
6) If I bid a proxy, I use an odd amount, like $103.54, something that is unlikely to duplicated, thereby not giving the other buyers any info
7) Research BEFORE you bid. If all the 6" like new Colt Pythons are selling for around $800, expect to pay around that price. Don't be upset if you don't win with you $500 bid.
The internet can be a great place to find items you are looking for. Just takes time.
Snake