I'd watch ebay for ones you are interested in and see how much they end up selling for. Sometimes they go for more, but at times much less. As Messersmith mentioned. Often the posters will end up going for more than the knives.
Many, if not most of the 80's and 90's Remingtons were made by Camillus. I have found these to be good knives with the best, to me, being up through the early to mid 90's.
If you like them, then collect them and pay what they are worth for each particular speciman to you. If you are wanting to collect them primarily as investments then I'd look at something else. For everyone that sells on ebay for a high price, another bunch just sell for an average price.
On the ones you mentioned above, you might see if the shop would give you a better price, especially if you bought more than one.
That may not be a lot of help, but that's my dos centavos worth.