It depends on which package you get. There are 3 packages. America's Top 60, America's Top 120, and America's Top 180.
Top 60 is $26.99 a month.
Top 120 is $37.99 a month.
Top 180 is $47.99 a month.
There's also a small fee to "rent" the recievers from them. If I find our bill I'll tell you how much that is, and if there are any other costs.
Edit: Apparently it's more than a "small" fee. Looks like it's $5 for each reciever.
Our bill is:
Digital home plan with America's Top 180, 4 Recievers - $67.99
Fox Network - $1.50
Superstation Package KWGN - $5.99
State/Local Tax (Sales/Gross Receipts) - $4.53
Total bill: $80.01
So, if you only get the America's Top 180 with 4 Recievers, depending on your state's taxes, I'd say it'll cost around $70 a month.
As far as if it's worth it, it depends on how much you watch your tv. Since I live in the middle of nowhere, and there's absolutely nothing to do, I watch a lot of TV. So it is worth it to me.