I suggest you go for the Xbox right now.....as the Games line up and Graphics are begining to give it a boost and a good edge over PS2.Also Hl 2 is rumored to be around on Xbox and GTA:SA is no longer exclusive for PS2 alone and is gonna set its feet on the Xbox this June and hence it will definetly be a worthful buy

Plus Specs wise Xbox sure has the best advantage over Ps2 but game's Library Wise Sony mostly has a good range of titles for itself
The Modded Xbox must be costing around 14k whereas the PS2 (Slim-Line) will be around 11k atleast.