great, since this is in line with my current understand and to avoid walking in even bigger circles, so lets continue with my original example
I want to buy 100 shares of ASICMiner at 5 btc/each , this is 500 btc in this example
I want to participate in a decentralized stock market where this company is denominated in bitcoin, listed in its bitcoin price, and trading in bitcoin
How many mastercoins will I need to participate in that 3rd layer application and facilitate the transaction?
How many mastercoin will the seller need to participate in that 3rd layer application and facilitate the transaction?
How many mastercoin will the issuer ASICMiner or ASICMiner-decentralized-Pass-Through need to have listed the security?
did I miss anyone that may need a balance of mastercoin? a market participant? a transaction fee? anything?
someone should be able to produce a finite number or equation for how much mastercoin that I or any of those market participants, or anyone ever, will need
You would need a Bitcoin pegged Mastercoin based virtual currency for that, which you could buy using Mastercoins. Let's call this pegged currency MasterBitCoins (pegged 1:1 to Bitcoin). You'd be required to buy these MasterBitCoins, pegged to the value of Bitcoin, in order to trade AsicMiner stock. This would mean in other words: convert fiat/crypto to MSC and then convert MSC to the desired amount of MasterBitCoins.
How many Mastercoins you would need depends on the value of Mastercoin at that given moment. In a year from now 1 MSC might buy 2 Bitcoins, who knows. Should MSC trade at 2BTC per 1MSC, you would need 250 MSC to buy 500 MasterBitCoins in order to buy 100 AsicMiner shares.
Not really sure about the other questions. Still trying to get more info myself.
Risk factor: A less convoluted protocol will come into existence obliterating the demand for Mastercoin
an alternate technology enables issuing securities, contracts, etc on decentralized exchanges without the need for any additional currencies.