Hi I am also not quite sure what they are worth hence was looking for offers. These belonged to my late Grandfather and my Grandmother has asked me to help find them a new home. I have been watching ebay and the cheapest I have been able to find a set for any 1 year (6 issues) is about $15. Some single issues from the time periods I have go for up to $20 each. I've got a complete collection covering 16 years which is nearly 100 issues.
So if we said 16 years at $15 per year plus shipping I would say in the neighborhood of $250 would be fair to me and a great deal for a collector. I would think that is in the ballpark but I'm not sure, I'm willing to listen to any offer.
Like anything, I guess they are worth what someone is willing to pay for them.