Would good condition Life magazines from the fifties and sixties have any chance of being purchased if placed for sale on eBay?

You should research it and find out. Just do a search on eBay for your specific date of the magazine to see what they are going for. Then use the column to the left to click "completed listings" to see what past auctions sold for.

I believe there may be a market for your magazines if they feature some famous people and events.

If you are going to look at the completed listings, you must be an eBay member and sign in or create an account. If you do decide to list these on eBay, be sure to list the exact condition of each magazine and take lots of photos. This way, the buyer knows exactly what they are bidding on.