I think the cheap price tag was because everyone knew that they wanted to get rid of him and there simply weren't a lot of teams that needed a starter PG. Houston was desperately going after Dwight Howard and a lottery pick is a better trade asset than a player for a team doing a full rebuild. If they had landed D12 with a package that included the Raps pick, then paired him with Lin, they would have had the makings of a roster that would have been an upgrade.
Also Houston decided that McHale was the coach they wanted, and him and Lowry didn't get along for whatever reason. Be skeptical, but I assure you that faith will be rewarded with this player.