That one may be a case of "a little knowledge is a dangerous thing."
If the seller was a general seller of second-hand items, he might have no idea at all of the kit, its history, whether there are a lot of them generally available, and so on, and he might just slap a sitcker of $10 or $15 on it. But this one may have done a little bit of checking and have seen, "Out of print," and decided that he could ask a lot of money for it.
If you're interested in that kit, and you're patient, you'll find it for a price that won't be as outrageous. If you're interested in following this particular auction and seller, just to see what happens, you might want to add it to your watch list, and track it through the end of the auction. See whether it sells or not. If it doesn't, see if the seller lists it again, for a reduced price. It's interesting to do, and you learn a little more about the second-hand market for things.
There's an author, a collectibles expert, named Harry Rinker, originally from our area here, and he came up with "Rinker's 20-Year Rule" for collectibles and that is that for the first 20 years of an object's life, its price is purely speculative. After 20 years, enough examples of the object have been disposed of that there is a remnant, and prices become more stable, more fixed, until enough time passes and the object might become a true antique. I think that rule applies to any second-hand item, with adjustments for the subject and the market.
He has another rule, too, which I find to be a valid observation, and that's that for items sold on the second-hand market, the price is whatever the seller and buyer agree on at the time of the purchase. Sure, there are guides, and you can track sales of an object, and decide for yourself what you're willing to pay, or as a seller, what the market might buy. But it's still too speculative to say that the item's price is fixed and unchanging.
In any case, for this kit, I'd probably go up to $30 for it, just based on my own observations, my own preferences for what I like to build. If I saw it for a really cheap price, say, five bucks, I might buy it more just to say I got it for five bucks (heh heh).
Best regards,
Brad