Summary

For this build, I used 2 Ikea Lack tables with the legs on one cut down to give 28" of top to bottom clearance.
The windows are 11"x14" thin glass panels from Dollar Store picture frames.
The white panels are 5mm thick Elmer's foamboards 20" x 30"

The left panel is designed to be clipped in place to provide easy access
The from panel is hinged. I assembled the hinge with 1.5mm diameter wire again from the dollar store.
The back and right panels are secured in place with double sided tape.

Total cost in Canadian dollars

IKEA Lack tables used - $5 each so $10 total. (They retail for $15 each new)
Dollarama 11x14 picture frames x2 (2 glass panels per frame) $9 total.
4 sheets of foam board $5 total.

The only other costs were things like hot glue, tape, filament, etc