RE: A Smart Contract Platform Without Transaction Costs or the Need For 'gas' Will Finally Offer Proper Incentive To DApp Developers. An 'Ownership' Model Will Always Be More Efficient Than A 'Rental' Model In Terms Of Entitlement From Stake.

[ikhlaq]

Just to address the development costs that you mention.

Ethereum allows developers (well anyone) to set up test networks on which they can mine test ETH tokens (https://souptacular.gitbooks.io/ethereum-tutorials-and-tips-by-hudson/content/private-chain.html), which can then be used to test dapp's before being deployed.