I've done some more hunting about for pre-made VIP modules.
I have seen mention of VIPs going for $5 to $10 per square foot... (that I'd like to find!).
However, I have found a company that appears to specialize in refrigeration parts & supplies, presumably for custom refrigerators... maybe.
But they do have a VIP pricing page and the prices are not at all as discouraging as has been presumed.
For instance, VIP sized at 23.75"x23.75"x1" for $60.
and VIP Panel 32.75" x 24" x 1" for $40 to $70 depending on quantity.
And, they will make custom sizes.
HERE'S_THE_PRICING_PAGE
Best,
-AC