Microsoft Storage Spaces Problem

[Byt3]

Storage Spaces from Microsoft has this huge problem where a server needs to have two controllers. One to hardware mirror the OS and the other to non-RAID pass through to Windows Server 2012 R2, I find that this is difficult find a configuration for.

The only alternative I've found is to get an external HBA with a DC3700, but that adds an additional $3000+ to the price tag. It's not very cost efficient compared to just purchasing a storage appliance.

Am I missing something?