I'm looking for the cheapest gigabit based NAS solution that supports B2. Any suggestions?

I'm thinking about replacing my aging Core 2 Duo laptop running Plex with an attached USB hard drive and BackBlaze with a combination NAS with Gig E and an NVidia Shield. I would use B2 for backups.

I have gigabit internet up and down and a house wired for Gig e throughout.