How much did your side mounts cost to make? Can members of hyperstrada.com commission you to make some?
Thats a loaded question
I only bought the SW-Motech hardware kit for the Monokey system, which costed me about $50 + shipping ... the rest costed me "nothing" since I already have a bunch of material, CNC, lathe, tools, bolts, etc ...
I mainly did it because I could not find any online store that would take the roughly $300+ to ship me the ready made stuff (top and sidecase mounts) from either Givi or SW-Motech ... no one had them in stock ...
So to answer your question I can certainly make a few more of these at about ~$100 + shipping for the plates and the custom aluminum spacers ... provided :
1) you don't mind the original color of the material (this batch is blue on one side white on the other ) ... easily sanded or painted to whatever you want ... I just hit them with a scotchbrite wheel on an angle grinder and thats it ..
and
2) you get the SW-Monokey hardware yourself (seems to be available all over the place).
SW-MOTECH sidecase adapter kit for Quick-Lock sideracks (GIVI Monokey/Kappa) | TwistedThrottle.com
As another poster hinted ... there is not much to these things and if I were to put an entire kit together with all the exact hardware, finishing, small loctite baggy, instructions etc ... I would probably be very close in price to what Givi and SW-Motech sell them for ...
So I guess what I'm saying is if anyone wants a complete mounting system for Monokey (top and side cases) for roughly half the price and a bit of elbow grease to finish these (finishing required only if you care for aesthetics and think that the
RED on your strada doesn't go well with
WHITE and
BLUE 
hint hint) then PM me ...
Migrane