I'm sorry to cross-post this from the Abraxas market's subreddit but I feel this need more visibility:
I'm not sure how DoubleAces hasn't already been banned or investigated simply due to the sheer amount of feedback by users stating they never received their orders. Take a look at his vendor page and you'll begin to ask the same questions .
It also seems his vendor rating is artificially inflated due to users changing their review text but not their original 5/5.
Everyone's been saying to avoid him. Word is he's just some renamed old scammer (Dr Nodsense or something). The product is similar, and he ships from the same location. Either that, or he's some new vendor who's in over his head. He's mentioned all the time in the Abraxas forums heroin thread, and everyone keeps saying to avoid or just stick to the escrow listings.