Are MN requirements going to remain at 1000 DRK? If a year from now DRK is 10x the current price, I fear there may be less MNs to support the network if the buy in gets to high and some earlier investors sell out.
Yes, masternode requirements will remain at 1000 DRK, it is not only about the number of masternodes it is also about the amount of DRK required to sybil attack the network, so a lower drk collateral with a higher number of nodes amounts to the same thing, for example: 2000 MNs @ 1000DRK each is the same as 4000 MNs @ 500DRK.
Plus, recurrent revenue passive income beats cashing out any day. If the price of DRK goes really high it means the MNs will be bringing very nice monthly profits while you keep your capital, so why close your masternode unless you really need to spend the money.
In the end, the market will always find its price, if some people sell because the "buy in" is too high, then the "buy in" won't be too high for long and price will adjust so new players enter. Supply and Demand.