I have telemetry on my Airtronics MT4 but I never took the time to actually set it up and use it.
You could look for some used radios in your price range that would give a very decent upgrade. Look into the Airtronics MX-V. It's a VERY nice radio for the price that will do everything you need it to. Seriously, I looked up the settings you can change and everything I use on my MT4 is available on the MX-V. They can be bought on eBay for about $75 with a receiver. A steal, in my opinion.