How many coins need to create a masternode and how many coins need for MN/POS?
coins can be active in a MN that mean they dont participate in POS
the collateral to run 1 MN will be 10000 DMD and it require a static IP
VPS able run a masternode or even multiple are very affordable in case u have no staic IP on ur private internet
POS will work on dynamic IP too and even lower amount of coins will successfully find POS blocks from time to time
the reward balance will be in a way that if u compare 10000 DMD run in a MN and 10000 DMD running in POS mode
the MN will only have a slight higher reward if enough masternodes are active
if the amounts of MN is to low they get more rewards as incentive
if to much MN active its better run coins in POS mode
and this balance will be manage dynamic each block based on amount of coins in all MN together compared to total coins
the exact numbers will undergo heavy testing in the testnet phase to be able launch with a fair system that rewards any contributor
no matter if he run POW POS or Masternodes
so you better start working on your 10k Masternode stash bois.