This happen a lot?
Do you think people like BitInstant and DeathandTaxes sometimes do large off-exchange deals to certain people at an attractive price knowing that they will in turn be the catalyst for bitcoin taking off (by web of extension)? Friends of these guys will hear about it and want to buy in, but I mean, supply of large singular bitcoin lump sum transactions without market slippage will become increasingly greater, and as a result, the price could at some near future point have a sudden "jump". I mean, plausible.
How do they (BitInstant, DeathandTaxes, et al. get the Bitcoins they sell is what I want to know? I know it doesn't matter so much to Bitinstant because they get a fee that can always keep them positive no matter they can keep replenishing coins knowing they have a consistent revenue and it won't hurt them unless the price dips too much, but how does DeathandTaxes do it?
D&T is a big miner if I remember correctly. He likely also buys some on an exchange. As long as you are willing to keep funds on the exchange, each time you sell you can make a purchase to offset it.