The point of them is to make it very expensive to acquire them. Imagine the following:
A:
- User asks "Should I create a masternode?"
- it costs $XXX, they would earn $X.XX/day. That's X days till they earn 100% of their investment.
- User buys 1000 DRK, creates masternode
- Price goes higher, 1000DRK gets pulled out of the supply
- Go to A
This is a feedback loop that I'm creating. We should add masternodes until the price goes really high and it's too expensive to buy the darkcoin to start a masternode.
Let's say after the feedback loop completes the price of Darkcoin is $5 and we have 1200 nodes. At that point we have six million dollar in masternodes, to gain 50% of the network to do an attack would probably cost much more than six million dollars, so it's not possible anymore.
The other problem is all nodes need to keep a list of all of the masternodes. We want a bunch, but we don't want more than 10k probably. If the requirement is too low we'll end up with a bunch of network traffic from all of the discovery chatter.
But the main point, the real reason to make master node expensive is so that an entity, such as a government, or such would find it difficult to gain control of enough of the network to compromise the system, right? If it were too cheap, it would be too easy for someone with enough resources to get control of the network.
In your last statement, "The other problem is all nodes need to keep a list of all of the masternodes. We want a bunch, but we don't want more than 10k probably. If the requirement is too low we'll end up with a bunch of network traffic from all of the discovery chatter. " does that mean that a person running a master node must register so the nodes can find them?
but don`t tell anybody else 
