"Auction or Sale"

I have this six different basketball trading cards which I think I got since I was in high school. They're not "GRADE A" in a point of view of a collector but I think its worth collecting. This six, was the only basketball trading card left and I don't know yet what to do with it.

What do you think I must do? Sell it or put it on auction? If I will sell it, how much do you think it would cost? And I will put it on auction do you think many collector will bid on it? What do you think? Please do so give me some advice on this one. Thanks!

.