SAN alternative for VMWare

Has anyone utilized something aside from a SAN to run their VMWare images off? We are looking to drop in two HP Servers and VMWare on them and run them off a SAN. Due to the cost of SAN though our CFO and VP are wondering if there are any viable alternatives (I.e. NAS) that can effectively run a VMWare. I can't think of any off of the top of my head. IF anyone can provide one or a good article outlining why to stick to SAN that'd be great.

Solution 1:

Just use the vSA

Solution 2:

I run a couple of virtual machines stored via NFS to a FreeNAS server and everything goes OK. You could use snapshots or HA independent from the VMWare Server.