It's not a question of partiality or impartiality. Even by your theory, the market value of this PowerBook should exceed the apparent $450.00 average resale price found on Ebay because buyers there recognize the risk involved in buying this way. So those prices should be lower than market price, not higher. Not that I entirely accept your theory. I challenge you to produce a better way of setting market values than an auction. This tells you what people are actually willing to pay for a given item. If that's not market value, then I don't know what it is.
I also would not presume to call someone's desire to purchase a product "silly" or "stupid." For one, he may only have $450.00 to spend. For another, he may really like the 12" form factor, which Apple hasn't seen fit to duplicate in any current Mac model.
Buying anything used is a risk, as I'm sure most people well know. Beyond that, I think you should set your personal value judgments aside.
Well first, I'm not saying that his desire to buy the computer is either silly or stupid; not at all. Again, he did ask whether $460 is a good price for that computer. My answer is: No, not only do I think that's a bad price for that machine, I think it would be silly to pay that much for something that old. Normally I would agree with you about setting value judgments aside, but a value judgment is precisely what the original poster asked for in this case.
But setting that aside, I will give you my unpassionate, brief economic analysis of this transaction, for your information and enjoyment.
eBay, IN THIS COMPARISON, is the prime seller, not the marginal one. So no, the price on eBay should not be higher according to my theory; rather, the price offered by the private seller (which, in this comparison, is the sketchier seller) should be lower. eBay is not a reliable place to buy electronics compared to Best Buy (for example); rather, when compared against the "some guy who wants to sell me his computer" option, eBay is simply less risky. So the market price ($450) is not necessarily indicative of the products overall value when sold by a more risky seller.
About market value: I did not say that $450 was not the market value, as you seem to have assumed. Clearly, it is. What I said was, just because that's the price on eBay, that does not actually mean that the machine is worth that much. Market price is clearly what people are willing to pay, but that does not necessarily equal actual value. The price of these machines may simply be a factor of scarcity, the same way that house prices in some desirable parts of the world (Vancouver or Calgary, for example) are a result of the scarcity of available living space, and house prices in other parts of the world (Florida) are a result of a glut of repossessions, rather than any of these prices being based on the houses' actual value.
This is not a concern for the original poster, since he has a captive seller. The seller could sell his machine on eBay for that same price, but he has chosen (for whatever reason) to try to sell to the original poster. If I were a buyer, the seller's choice here would probably give me some pause, particularly considering all the software he appears to be offering with the machine (which, in theory, should fetch a much higher-than-market price). But excluding that potential problem, the fact that the original poster has a captive seller gives him bargaining power, because scarcity is now on the original poster's side. The seller wants to sell specifically to him, and has a machine that he seems to need to be rid of in the shortest possible time, given he's selling machine+software at the same rate as the market price for machine alone.
So in this transaction, cash is scarce; the machine is not. Bargaining power belongs to the side with the scarcer resource (in this case, the buyer) The seller would have to go to trouble to find another private buyer (not wanting to sell on the open market), which would indirectly cost him money (as would changing his mind and selling on the open market). Couple the desire to get the largest amount of money possible from the buyer that's currently on the hook with the fact that any private buyer the seller chooses automatically has the scarcity power in this equation, and the result is that the buyer would most likely be able to force the seller to sell for a lower price than the initial offer.
Conclusion: $460 for THIS machine is a bad price. The original poster can almost certainly have it for less. Given that the seller does not want to pay commissions or spend the time selling on the open market, and likely does not want to go hunting for another private buyer (with associated direct and indirect costs), the absolute highest price that the buyer should consider paying for this machine is:
market price - eBay commission/listing fee - depreciation since the start of the transaction
If the seller is not willing to sell for less than the price that equation results in, the buyer could still buy the machine on eBay for $450, and would be no worse off. So, there is no risk to the buyer in trying to get a lower price from THIS seller, and consequently, he should not pay THIS seller $460 for this machine.
