Im not honestly sure. Ive only just got back into the game and the last time I was racing prior to that we were on 27mhz crystals!!
So my knowledge of the technical aspect of 2.4ghz and binding is limited. The Tx does have the bind button on it and there bind plug is in the box so I would assume (
) that if you had a compatible spektrum rx then there shouldnt be a problem. Probably best to check that with someone more knowledgeable than me though!
With regards to price... I bought the Tx & Rx combo for £70. So say half for the Tx is £35. Then say as its second hand (although basically brand new) £15 off.... I would let it go for £20 + p&p special or recorded delivery with Royal Mail.