As others have pointed out, anyone can charge what they want for things they sell in their store (as long as they don't have fair trade pricing on them, or they are guilty of illegal price undercutting).
As Allen and others have pointed out, with trains it depends on what we value something at, we might pay more for something because we want it now. If you get a hankering for ice cream at 2am, is more expensive at a 7-11 then a supermarket. I have bought things in the train world because I know I didn't see them much, I bought the old Erie Wreckawanna green monster MU units off flea bay because at the time, I couldn't find them, and paid prob more then I should, and I was happy (ah, the memories those wrecks bring back....
.
In a sense, trains are not commodity items alone, they have sentimental value, whether it is a locomotive or the train line that touches you, it is emotional (on the other hand, I don't think anyone gets all emotional over a 5 year old pc that some yahoo wants to charge a grand for).....so yes, buyer desire plays a role as does supply and demand.
There are dealers, including one where I live, who charge MSRP or above, they aren't cheap, but I will buy stuff from them because they support it (I bought a way out of warranty engine from them, it failed, they fixed it, on the house), and I like them, so for things I will pay the freight, happily. Other things he doesn't have or where the price is simply out of my range, but I can buy it in my price range elsewhere, I will.
On the other hand, dealers or business people aren't gods, and people have the right to criticize them, too, even if others don't feel they should. The idea of businessmen being gods died a long time ago, back in the social darwin era of things , and what they are legally or justified in doing is one thing, but customers have the right to criticize them, too. It is like the opinions on here, others say things I don't agree with, and they are within their rights to criticize me, and I them. Ultimately a business owner has to make that decision, but then, as others say, I don't want to hear shop owners whine about how hard it is to do business, either. I don't know the shop in question, but if he is trying to pass off 8 year old stuff that isn't the same as the replacement, then in my professional opinion he is foolish, because people know what prices are, and if they can buy, maybe in his shop, a ps3 version of the ps2 version of the same product, who the **** would pay the same for a ps2 (or ps1?) . Who would pay the same for a TMCC version of a lionel engine as the legacy equivalent? The thing about replacement pricing is the goods have to be the same thing basically, if it is totally different things, it is apple and pears...will someone be willing to pay that price for a ps2 model? Maybe, and god bless them, but if I was a retail consultant, I would tell him to get rid of as much dust collecting inventory as possible, unless something has proven itself to be a heart wringer (for example, an older generation hudson might command premium pricing).
Funny, some of the people on here mention gas prices and that is actually a classic example of commodity pricing, where it is identical. The gasoline you buy today was paid for a while ago, the oil and/or the gasoline were bought by futures contracts months ago (oil companies, for example, buy crude 6 months out, they buy oil for november delivery in april or may or further back), and that sets the price at delivery, a gas middleman might buy gasoline based on futures contracts way back as well. Prices of oil and gasoline are set on commodity markets in futures trading. When the price of gasoline shoots up, usually it is because the price of oil has surged in current month trading (so called front month), and the providers adust current cost based on the cost of buying it in the near future. It is why when oil starts shooting up in price oil companies return such ridiculous profits, they are selling oil or gasoline at a price they set x months ago, and are selling it today at x+ Y%. I also have heard how oil companies can lose money if the price plummets, i.e if they buy it at X in April and by november it is .80x, but what that leaves out is energy companies hedge purchases in such a way that if the price drops, they still make money (complex derivatives trading, where the derivatives contract costs them little, but if the price plummets, makes up for the losses). Thing is, gasoline is gasoline, oil is oil, it doesn't change much (if it is a certain grade of oil, low sulfur is priced different then Saudi high sulfur crude).
