I was thinking about a setup like that at one point as well... Only I was going to search Craigslist for a cheap/used air hockey table, reverse the air flow, and remove the legs!
thats a pretty cool idea to be honest! might be a bit bulky though for not much reason. the above frame wouldnt be much bigger than the size of a display frame.
even though mine would take a little time to put together, its not much work at all really. and would be cheap as chips.
all the materials would come in under £15. although maybe if you were buying silicone sealant it might be under £20 in total?
also curious to know where you found the rolson tape?
rolson is a cheapie tool brand over here in the UK. the tools they make are BOBBINS, i wouldnt give them to kids to play with, as they would break too easily haha