Prusa i3 sheet components for a build for the #vancouverhackspace machined from 1/4" Mic6 cast aluminum tooling plate.
Shiny! But if it was mine I’d be really tempted to have a control screen that flashes “12:00” when the print was done. 
You have some tapping ahead of you. :-). Remember my first set of plates I ran off a waterjet. You really are going to be happy with the build. The plates look amazing!
I’m not doing the build, the plates are my contribution to the build. There are ten m3 tapped holes in the outer plate as requested by the builders. They were tapped in the mill when I cut the profile.
What are the dimensions and what would you charge for one more? 
The large piece is about 14.5" square. The printer will have a 200mm bed. if the Hackspace people like it, and there is a group buy, it would run $110 for the set.
Yeah, I’m seeing $60 for a 13"x13" tool plate blank here locally. It’s what I get for making a 1 foot print volume.
@Mike_Miller Just FYI, if you’re OK with 6061 (instead of Mic-6) then you might want to check out OnlineMetals.com. It looks like they do custom sizes and 13"x13"x0.25" is only $50.70.
http://www.onlinemetals.com/merchant.cfm?pid=1248&step=4&showunits=inches&id=76&top_cat=60
$10 plus gas to make sure it’s not bent in shipping. 
Or add an OX to your tool chain, +$1000.
The Mic 6 for this was $65 at 14.75 square. from my local supplier
@Bernie_Koestlmaier_C nice looking guitar in your profile photo! Fender Telecaster?
No, it’s a Liquid Metal Guitars Tele. Machined by my machine shop.