27mhz Am has always been popular in beginners or rtr type equipment . it has mostly been replaced by 2.4 ghz equipment
27mhz FM was popular at the top end of racing guys a few years ago when 40 mhz was also at its peak . it meant less xtal changes for those using 27mhz
again it appears to be almost wiped out with the emergence of 2.4ghz
i have a 27mhz FM set still i let my 9 year old daughter use it
equipment appears to fetch very little these days
regards dave