I looked into getting DirecTV ... Biggest thing is that you must have a clear shot of the Southern sky.
$31.99/month buys you 110 channels, but none of them a local channels, an additional $11.99 is the cost for the local stations, but depending on your area you might not get all the local stations. Here in the Washington DC area we get ABC, FOX, NBC, CBS but not the WB or the UPN.
You can check by entering your zip code here:
Link
In the NYC area they get everything with the local stations package.
If you dont get all your local stations you can consider keeping cable and going down to their cheapest package, the basic cable package, which is just local stations for around $10-15 a month and then getting satellite ... Roughly the same $40/month but now you're getting 110 stations plus the local stations and if you so desire you can get other stuff like all the sports games (I think those are like $4.95 per game unless you go with the packages).