I work for a small production company, but the only machine we have that would do these parts is a haas vf1 mill. Probably can’t offer even close to pricing that a waterjet can offer.
Someone posted about wanting a plasma cutter attachment for the MPCNC. I run a Torchmate at school and I don’t really see a reason that the MPCNC couldn’t have a plasma cutter attachment. The Torchmate uses two nema 23 steppers the x axis and two on the y. The z is jut manual adjust. Of course you need to build a base designed for plasma cutting instead of mounting it to a table, but you could make a bunch of these parts just as fast as waterjet. Even the cheapest plasma cutter should do this job just fine. If I get in some 1/8th steel plate I can make a test piece.
If the machine was mine, I would do it for a little more than material costs+shipping, but I can’t offer that since I would be putting hours on a machine that doesn’t belong to me and the consumables for plasma cutting aren’t super cheap (though better than breaking endmills). Waterjet would be a cleaner cut initially, and I would probably make the holes undersized with the plasma cutter and then drill/ream them out to size.
It could be done out of aluminum too, but you would probably want a water bed because aluminum tends to make a mess by melting to the slats holding the piece up. Plus it melts so easily that it can fly up into the torch and clog it which burns up your consumables.