I had issues buying somestuff. Was a paypall update and click on some new agreement thing. Once I did that, no problems and have bought APOS, SABOW and some dlc's off them. As a side note I bought the british dlc for arma 2 oa off them way back which is why I probably had to do a click o rama to find new agreement thing. Was not exactly straight forward but I think was a paypall issue as they run the credit thing........well one way to do it.
Steel Armor: Blaze O War (SABOW)---
ISABOW mod. Check Graviteam forum. New AI vehicle M113a1 with recoiless and M106a1 self propelled mortar carrier. Much of other little stuff too.
Requires AUG SABOW patch from Graviteam. Enjoy