Hi im not a collector but I have things my father collected, I have a album says u.s.proof set,it contains 1956,1957,1958,1959,1960,1961,1962,1964,1963 isn't there but two sets of 1960 are and a gentleman offered me 185.00 I don't know if that's a good price or not,they are in mirror looking condition,
I posted this in the other (old) thread prior to seeing you had started one of your own (good idea).... Just to be clear, is it an "album of proof sets" or complete sets of proof coins residing in an album? If original complete sets, a fair starting point may be to search completed eBay listings, taking the low average for each, and total up to give a likely best-case retail number. However, it should be understood that when selling multiple sets you're likely to get less overall than if sold indivually. This, of course, is very generic advice and does not take into consideration the quality of the individual coins or any other factors that can contribute to increased values or prices. For that, we would need to see the coins in order to determine if there's any potential.
Welcome to CT and sorry to hear about your father. That price seems a bit thin. Your best source for market pricing would be eBay completed listings. I'm sorry to say though that these are very plentiful and you may be a little surprised how low they can be bought.
On average, I see these sets sell for anywhere between $20 to $50 each. Depends on the coins and dates.. At the low end of that, I would say that offer would be light, but if the offer was from a dealer needing to make a profit, maybe not so. All of these sets were minted in Philadelphia and it's a crapshoot on the quality you got from them. There are a couple coins it those dates that could bring quite a bit more, but you would need a knowledgeable numismatist to tell you if they are there. Edit to add: I do believe that I am the only person who could order 10 sets from the mint and every one be junk.
To emphasize, look at the actual prices for proof sets that have already sold, not the asking price. They often have little relationship to reality.