If you visit the ea forums they have a statement about auto buyers, basically they trace and permanently ban anyone using them. I'd highly suggest not bothering with one the way the market is now + it's not worth risking a ban.
Yeah, you can get banned, yet a lot of people still tend to use them. Some players I put on auction earlier were literally bought as I pressed "list item"
It's a shame how hackers and scammers can ruin games like this, and EA simply don't have the time to be able to hunt down everyone so a lot of people probably get away with it