no specifics have been released but in the q&a Igor made it clear that masternodes are able to affect the network stability in both good and bad ways.
I believe the bad way could be that there are too many masternodes coming and going because 1. you don't need a lot of coins to start one, and 2. because they don't give enough income. That's why I believe the minimum amount of coins will probably be over 50K. They're not going to want small bag owners starting masternodes only to sell their bags again because they're barely making a few dozen sonm a month. The incentive of holding a masternode is the passive income, but if that's neglectable, people are going to sell their bags when prices go up, which results in the network not being stable.
I disagree. How do you know if network will be unstabile, if number of masternodes is so big that it doesn't really matter if they are coming and going?
Also: Selling bagowner's bags is not a problem if atleast half of them keep their nodes up.
I understand where you're coming from, but you're focussing on the wrong part of the argument. There's only a finite amount of transaction fees that can be distributed over the network. Large holders (+100K) wouldn't be interested to keep a masternode when the profits are too small because there's a bunch of small masternodes getting part of the share. It would be really easy for those holders to sell their bags and go to another coin. I presume you don't hold more than 20K sonm, so I understand you want the number of necessary tokens to be low, but from an economic aspect it's a lot more interesting for the sonm network to have a smaller amount of bigger masternodes that earn decent money, than to have a ton of smaller masternodes earning shit money. The main goal for masternodes is provide security and stability to the network, and you can't expect people to hold their bags and provide security if they only make 20 sonm a month.