I've never bought clones before, and don't even have a ballpark price for a decent strain clone. $10 each? $100 each? how large should they be? I really don't know, lol.
Here in socal, clones go for about 15 for pretty good strains, 20 if its something super good. Alot of the time though they are sold in lots (50 for $200) or something like that. They shouldn't be to big. Maybe 6-12 inchs.
Ditto on what kill a jedi said. One thing though, dispen's tend to pick & bag before you can really check it out, look at it/them, try and pick ones you can see some root growth on, the first time my newb arse bought clones I got a dozen from a guy, looking back on it I realize they were probably clipped & stabbed into dirt cubes the same day and the ones I've gotten at the dispen's seem to be a little more developed. HTH, S.S.