Wine or Internet Start-up Shares?
You can buy good wine that will improve with age at a reasonable price, but you have to leave it undisturbed for a long period - preferably out of sight, so you aren't tempted - and at a fairly constant temperature. My best example is some 1985 Vieux Telegraphe Chaeauneuf-du-Pape that I bought in 1986 for about £6 a bottle. By the time we drank the last of it in 1997 it was glorious. What was it worth? I don't know (Berry Bros. & Rudd (www.bbr.co.uk) only goes back to 1994 and the 1997/8 is IR£20.78 in Findlater's). It might not have been all that much. But you couldn't buy it anywhere and I have rarely tasted anything so gorgeous ...
First bit of advice: Get some advice! Go to a good wine merchant, find out who knows most about it, and talk to that person. Some wines don't keep at all (Beaujolais nouveau, for instance). Only some versions of other types will age (or even ever taste reasonable at all - there is some awful tack from Chateauneuf-du-Pape!). Different years will have different ageing capabilities. Different grapes also exhibit different characteristics. And to cap it all, a lot of good wine is nowadays made for early drinking. A useful rule of thumb is that if it tastes good now it probably won't keep. You need a good balance of tannins, fruit and acid, and some of arcane trait that I'll call complexity (but won't try to explain) lurking underneath.
Having said all that, the merchant will try to sell you what he stocks, so you may want to read around. Jancis Robinson of TV fame has a great book with "wine timelines", and Robert Parker has lots of advice for the serious wine buff.
Buying en primeur will probably be recommended to you, especially around early summer. This means buying wine that's still in the cellars in Bordeaux, and paying the taxes and carriage charges when the wine is delivered a couple of years later. The major merchants send out catalogues every year, and it can be excellent value.
I have had experiences where it hasn't been, though. Watch out for the hype; every year nowadays seems to be the best this decade/century/ever. And look for bargains. To spare blushes I won't name the overcharging parties, but a quick comparison of this years offers (north and south of the border) showed the best bargain after taxes, charges and currency differences to be Chateau Teyssier St.-Emilion from Searson's in Dublin. It was 15% cheaper than the dearest and 7% cheaper than the next best price. It pays to shop around.