Sure it makes sense. You could probably sell just the transmitter on eBay for $30.

It just depends on how many Tx's you want lying around I guess. Once you've bought equipment for 4 or 5 planes, all those tx's get in the way. You'll find it's easier to stay on one frequency too. (Nothing like bringing the wrong tx to the field.) I use one computer tx for up to 6 planes right now.
Dennis-