However, I wouldn't sell the remote. If you ever decide to use the receiver for two TV's, you will be SOL, and would have to get another remote from Dish, or E-bay. Either way, I wouldn't think it would be very cheap, perhaps more than you got out of yours--perhaps less. And, if you ever decide to sell your 622, it would be better to have all the remotes etc...
Of course, you can't sell the second remote if you lease the 622, i.e. you didn't pay $700 for it and instead paid $299, which is the lease fee. If you do or did, if/when you cancel Dish, you will have to return the receiver back, and I wouldn't think they'd accept it without both original remotes.