Well, I'll take a stab at it for you. I've been doing some studying on postwar Lionel for the past year, and I have purchased some postwar stuff and learned a little bit (emphasize "little").
For one thing, as Iron Horseman says, your set is not a valuable collectible set that collectors are looking for. For one thing, the economical 242 Scout loco probably has a plastic body, frame, and more than likely a plastic 'motor'. From what I've read and understand, these all-plastic locos are NOT overly friendly for rebuilding should something go seriously wrong with them. Which is likely a big detriment to their value and collectibility, as compared to the die-cast metal postwar steam locos with their metal frames and motor mechanisms.
But, looking at your pictures, everything looks relatively clean for its age. If your loco runs, that would be a plus. You definitely have extra track, as the original set would not have included switches (turnouts), or more than a simple oval for that matter. I assume you don't have any original boxes, as I see none in the pictures. This can cut down on the value of a set.
All in all, for everything I see in the pictures, I might guess your set to be worth somewhere between $100 and $200, give or take, depending on the buyer. Of course, I am far from an expert at this point in my postwar knowledge, so take my rough estimate with a grain of salt and get some more opinions on the value besides mine.