You're going to have a hard time staying below $60 per month unless you REALLY don't do much internet. Verizon Wireless 250 MB plan is $40 per month. It's easy to use up 250MB with modern web pages. The home page for SatelliteGuys is 450kB all by itself. If you're using the prepaid service, each day is $15, and each week is $30. So, if you're at your place two weekends a month, you're paying $60. You could get the one month prepaid service at $50, and that would give you 500 MB of data, so for $10 per month more than the $40 plan, you'll get double the data. I don't know how much hassle it is to sign up each month or each week, so you'll need to decide your tolerance for phone company signup fun.
Having said that, however, IF you have a good signal, the Verizon Wireless internet works very nicely. My company provides a little internet USB device when we're on call. The speed is great, and there is no latency problem (unlike satellite). If you have three to five bars on your voice phone, you're almost certainly OK for data. If you only have one or two bars, your data access may be spotty. If you can borrow a USB device from somebody, try installing it on a laptop, and testing at your place. You need a minimum signal strength of -80 dBm to get decent internet. (-70 dBm is stronger, -90 dBm is weaker) Run a speed test while you're connected, as sometimes that affects your strength measurements.
HTH