Can you set profit margin to negative numbers?
Well, there's an option to set the profit margin. Right now, it's default at 150% of the item price, and unchecked. If you change the minimum profit to something really low, like 100, and the percentage at 100%, it would essentially buy everything. I've did it myself a couple times.
But you do need to babysit Abrosia... I don't know if having this feature as an automatic thing would be a good idea. I definitely wouldn't want Abrosia to constantly buy up unprofitable items while I'm away from the computer.