100 000 Is not too much money? With such figures, even if everything is put on the masternode, you get 5,000 masternod. How does this tell on the decintralization?
Masternodes do not inherently affect the decentralization of a coin as they are constantly in flux transferring in and out of ownership as people choose to "buy in" or "cash out". Also masternodes do not always = the ability to affect corporate governance or business decisions. Keep in mind right now Dash currently has aprox. 4000 nodes running and to purchase a new node is outside the scope of what most would consider "affordable". This directly affects decentralization since Dash has committed to including nodes in corporate voting decisions.