It depends on what route you take, and with which network provider. As I wanted properly unlimited (e.g. no FUP) and have a good coverage I went with a standard Three UK SIM only deal, obviously you can use it in a phone but it works just the same in a 5G/4G modem/router. After cashback incentives, it costs me ~£4 per month, I think the best you can find it now is about £10pm, maybe a little bit less.
Best thing to do if you are moving to it as a main connection, find out by testing the various networks in your home, preferably using the same device in the same locations at the same time of day, same day of the week etc. Getting a PAYG/SIM Only 30 day is a good starting point just to complete the testing with, if you don't have access to all the main network SIMs already, using nPerf for speed and stability testing is recommend above Ookla speedtest, and checking the CellID on Cellmapper.net will help you resolve which mast your are connecting to and what the available connection and bandwidth are like on that mast, how far away it is etc.
4G/5G is a great deal more involved to get setup than fixed line, but done properly, and with the correct kit setup right can give you some exceptional results.
c0XBW3A by mikehhhhhhh, on Flickr
