Alrighty!
First things first, if you are going to be doing a decent amount over Wifi do your devices support Wireless N?
Secondly, if possible I would really try to find a way to wire the HTPC to the router, the speed differences when it comes to streaming are pretty significant, especially with anything in HD (I actually just bought a gigabit switch to connect all of my PCs/consoles together for easier streaming instead of the 10/100 on my normal router).
What would you consider to breaking the bank >$100?
And what was the previous router that you had, so we can compare the specs/etc.