I too think that kind of money is out of my range.
But it got me to thinking:
Attachment 225338
Attachment 225340
'What if' instead of my 12"X12' glass plate was say a 3/4" piece of Plexiglas that had the pattern of the Pyrex baking pan routed out say 1/4" deep and then filled with Silicone. OR perhaps simply a piece of 3/4" plywood that was sealed and then the groove routed and filled with Silicone:shrug:
Then having say that glass plate coated with Vaseline and then clamped down to level the silicone and let the silicone cure for a few days?
I used feeler gauges and the widest gap between the glass and the bake-ware is 30 thousandths.
As my friend walleyeyman likes to say; "Always Thunkin"