You could take a look at Wifi radios similar to Tranzeo products:
Broadband Wireless Products - Tranzeo Wireless Technologies Inc.
Tranzeo went bankrupt and is trying to reincarnate under Charlotte Resources Ltd. The Tranzeo website is still active. You can likely get a pair of Tranzeo 2.4 GHz radios for under $100 from Ebay.
We had internet using Tranzeo for a few years. Our service was flakey, but that most of that was due to the configuration and a lack of understanding by the supplier. It was a complex system to get service to me. It went through three repeaters(total of 6 radios) before reaching my radio. Even so, we got got up to 3 Mbps.
Your setup would be a simple point to point between two radios.
I believe the radios use about 8 watts average with power fed through power over ethernet(POE) via a power adapter that looks like the old square "brick" used for modems, etc. If possible you would want to plug that adapter in to some source in your provider's enclosure.
Other frequencies are available. Higher frequencies such as 5 GHz have higher data rates but shorter range. Higher frequency units also are more affected by obstructions such as trees. The 900 MHz models will go through some trees but have lower data rates and cost more.
Our service was flakey due to the complexity and we changed to cellular when it became available. I owned four of the seven radios that served my place and gave them to the service provider when I no longer needed them.
Wireless radios should work for your situation.
For more information you can get the manuals from the Tranzeo website.