One way of thinking of a 1st series and a 2nd series as I've been told is to look at a 54 vs the 56. The body style changed tremendously. As far as value, all value is in the eye of the buyer. I'm not trying to be stupid on that point but it seems when it get to classic cars/trucks, it all depends on how much the seller is willing to part with it and how much the buyer is willing to pay. I was just offered a 57 with very little rust, sitting for a few years so not currently running, for a cost of just $2,000... There are Price value guides which do list pricings from auctions and sales which may give you a basic guide.
