don't bother with grading them.
use/age probably the difference if all backs are the same.
there are always 15-20 listed on eBay so use as a barometer.
i would make at least 3 lots if most are either very clean or very worn - the joker - the clean cards - the worn cards*(see below).
in general the joker will bring from 20.00 - 75.00 depending on condition (and series) and the others less
if i had the group i'd start the joker for 9.99 regardless and * package the other cards assuming decent condition as 4/5 cards in a lot for 9.99 or 19.99 depending on your level of risk taking. In general these cards don't sell for much as singles. If the cards are really beat - one lot and some prayer although the joker will always drive a lot.
no guarantees whether written or implied