I agree and I think that can be done. Again for $400+ that expectation is not out of line. I agree with you on the benefits for plexi, but we're not talking about a $20-30 piece of commercial wall art, so I think it is fair to expect glass and proper shipping to preserve it.My preference too "if and only if" it arrives intact. Knowing how these items get kicked around, it probably wouldn't unless they spend a lot more on packing material to ensure the glass arrives in a pristine condition.
Really, for that money I could buy actual functional units, install hip floating shelves & LED lighting and display them that way too. There are some really neat examples of that sort of display when DDG or Google searched but you are so right in saying that time is money, so really this would be an option if you were so inclined to do so and have the extra time to deviote to it.