This is a bad sign

http://www.boonex.com/unity/extensions/entry/Facebook_Ultimate_Module_All_in_One/

There is a few of them like this in the market. And you are right its a good look.

Is this proof that Houston is covertly trying to purchase Facebook items for his site? 

There's nothing covert about it.  I purchased this mod a while back, and have been asking the developer to fix a few nagging issues for months.  Perhaps he recently removed it from the market, and is busily working on the fixes.  Me, and about 25 other people would like to know what's happening.