I would definitely hit up eBay if you want something seamless. I do this all the time for the MX850 remote control from URC which integrates really well into Crestron control systems. I sometimes get them with 'bad buttons', but I fix them and they work really well.
But, picking up something like this for under $200 may well be worth the cost, especially if a programmer is involved in setting things up. Just have them program it, let them know you want it as a hot spare, and it'll be all set for you to go whenever you need it... Or at least, that's how things would work in my world.
Good used RTI T2X with charging cradle.
www.ebay.com