Can't see why you think it would be stolen. As others have said, the pet has been out for a while, and is the only store pet that's tradeable in-game (therefore acting as a way to legitimately "buy gold").
There's someone on my main server who almost always has one listed on the AH. I tend to buy them with gold that I saved on my main toons, then re-sell them on a high population server where I have an auction house alt parked for pet shopping. Seems a good and mutually beneficial arrangement.
P.S. Of course any tradeable pet works for transferring wealth between servers, but I choose the Guardian because it has a somewhat stable price compared to most TCG and in-game pets.