Yeah, it's hard to balance beacon costs, since it's not really the beacon itself but the modules that are resource intensive :)
I think wide area beacons with dedicated expensive wide area modules could be a balanced solution (as an addon or another config variable). Of course that prevents you from using cheap t1 modules in your beacons while you are scaling up (unless you have tiered modules, 'Wide area {speed, efficiency} module {1..3}')
If it's possible to limit module types per beacon type, I can help with some balancing and numbers if you want.
Anyway, it's a nice mod :)