FIP proposal: Allow storage providers to set *negative* prices for verified storage deals

[ThatGuyLLC]

Discussion following curation of issue: #123

Author: https://github.com/momack2
The Mission of Filecoin is to create a decentralized, efficient, and robust foundation for humanity’s information. As such, one of the core goals of Filecoin is to create strong incentives for capacity committed to the network to be utilized in storage deals for valuable data. To achieve that, Filecoin clients and storage providers should be able to propose and accept negatively priced deals - aka deals where the storage provider pays the client to store their Filecoin+ data.

Right now, demand from storage providers for verified storage deals (made by clients with FIL+ datacap) is very high, since it confers a 10x multiple in block rewards proportional to the verified deal size (which helps storage providers quickly achieve and maximize profitability). However, access to these verified deals is constrained by the number of new storage clients onboarding data onto the network. To compete for this high-value resource, miners should be able to offer not just FREE storage and retrieval for verified deals, but NEGATIVELY PRICED storage/retrieval deals.

Negatively priced deals (that share the 10x multiplier returns from FIL+ data with the storage client) will help attract new high-value clients to the Filecoin market, thereby increasing the network's utility and the overall number of FIL+ deals available. As @jbenet mentioned in his EthCC talk, this is a super exciting opportunity that is uniquely available in Filecoin. Instead of having to build these auction/incentive systems outside the deal-making structures of Filecoin, we should simply encode the ability for storage providers to set a negative ask price.