That deal is for a "blemished" rifle... I'm picky, so no way I would buy a blem rifle sight unseen for my first AR. Like I posted earlier, the piston is proprietary. If something in my AR breaks, I can run down to my local shop and get the parts to fix it, same day. That may not be the case with a piston AR. With that said, this doesn't look to be a bad deal as long as you can live with any cosmetic blem you may receive.
I bought one of these so called 'blems'. There wasn't a mark on the rifle. I subscribe to hickok45 on youtube and he had a 3 part review of lower end AR's, the AA blem from Buds, the Sport and the Ruger AR556. After some research on the AA I decided to buy one. It is one hell of a rifle. Smooth shooting, some neat features with the piston driven gun and it doesn't puke all over it's own plate. After initial cleaning, I've put ~500 rounds through it and have yet to notice any dirt or grime in the chamber or on the BCG since the exhaust gases don't reach the chamber.
The neat features are to do with the piston system. There is the standard setting, a suppressor setting and a New Jersey setting (as Hickok45 calls it). The suppressor setting restricts a little more gas from pushing the piston since there's a little more gas build up in the barrel using a Suppressor. The New Jersey setting makes it a single shot.
If I could only have one rifle, it would be the AA blem from Buds, hands down the best buy in that price, if you don't own one, you have no grounds to base any comments from other than pure speculation.
I went in to the purchase assuming Bud's cherry picked a rifle for Hickok45 to review, in his review he couldn't find a 'blemmish'. When mine arrived, my gunsmith/ffl says is this supposed to be a blem? As I walked in his shop since it arrives in a plain white box. I said yes, why? Is it all beat up? He says he really looked it over and couldn't find so much as a scuff on it. I've bought a few AR's, all new, all of them being factory rifles, not blems, and aside from a couple of them, all have had some sort of blemish on them in the form of a scratch, knick or rub mark. I don't worry about any of these things as I'm not holding these things with velvet gloves or laying them down on pillows.
I'm just offering this post to the OP as he asked specifically about the Bud's AA blem rifle, and this is my two cents worth on that particular subject.
As mentioned in their ad, you might get a government profile or an M4 profile barrel. Mine was an M4 profile barrel. It also included an MSAR 30 round magazine. I saw they bought another batch that doesn't include a magazine for a bit cheaper price. I like that the front railed gas block is upper rail height, although I scoped my rifle, love the way it shoots.