if clockworkmod recovery is still there you can ask the buyer if they want it or not
I wouldn't bother. If the buyer is experienced he/she wouldn't mind, that will save him some time putting it back anyway. If the buyer is not experienced he/she wouldn't need it, wouldn't know how to boot into it.
I sold my Intercept once in the description I stated that the phone is rooted, running custom ROM, if the buyer wants I can restore it to stock, the buyer emailed me and said that he wants my custom rom and custom kernel.