Absolutely 100% agree with kennym .Do your homework 1st. I'm not a Stamp Collector / Dealer, but do know that if you don't advertise them properly, you will get yourself into all sorts of trouble. It may be better to sell them individually or in sets, rather than "A Job Lot" . It will take longer, but IMO would be an advantage to you & the Buyer.  That way you 7 they know exactly what is on offer. Please, for your sake, do all your homework 1st. Hopefully you will get more advise from a Dealer or Stamp Collector as to how to go about it.  Good Luck 🙂