Yet more transceiver modules!
A search on eBay has thrown up lots of useful RF transceiver modules, not as low cost as the AM ones found by G6ALB, but nonetheless very low cost and suitable for local communications, Some are 100mW and some 500mW or 1W. The ones I saw were data units, but these should be suitable for speech with simple mods. I am unclear how some of these are programmed to the correct frequency. There is usually a choice of either VHF or UHF and I think some are essentially FM.
Put “UHF transceiver module eBay” into Google to see what comes up. Or try “VHF” instead of UHF. I was amazed how low cost these were.