"What it's worth" is a really fluid concept! A quick example - I bought a mint 127UH for $52.50 (plus shipping) a year or so ago, and sold it last week on fleabay for $42 (plus shipping.) So, apparently it was worth $52 and now it's worth $42.
Maybe there is a practical way to figure out what it really is worth... Start with "How much did it cost?" Well, it cost me close to sixty and some other guy $46.50. Between it's last two owners' costs, it seems to be worth $53.25.
You guys probably have a figure in mind, is fifty bucks close - I'll bet it is...
It's just my opinion, but I think collectors or consumers decide the VALUE of an object by figureing out how much money we are willing to part with in order to aquire the object in question. The guy who actually buys it decided how much it COSTs. If you figure out the average buyer's cost, you get to "how much it's worth."
Of course, this is a simplification of something much more complicated. Fair market value will always be volitile number because of shifts in consumer behavior, financial trends playing out, supply/demand shifts, new entries into the market, etc... But, averageing the last three or four buyer's cost's is still a practical way to determine what something is currently "worth."
So, watch how much a few 124s go for (same condition as your own 124) and get the average price (add the prices, then divide by the number of knives) and you will have what 124UHs are currently "worth" on eBay. You can do the same with dealers, but you can't use the price they ask for, you have to use the prices they sold for and that may be a little tricky to get...