One way to possibly get a case or two at a more affordable price, is contact a local sign maker, if there is one. If they make acrylic sign boards, they may agree to to at least cut the sheet for you, and possibly glue it too. A friend recently did this for some military regalia he wanted to display.
I'm in a similar situation, and even have a couple of part-built larger models 'on hold', so they don't get spoiled by dust whilst waiting for display cases. I've worked out that it'll be cheaper in the long run to buy a two-door, glass display cabinet, with seven movable shelves, and one fixed, and LED lighting. This would hold an average of 25 to 40 models in 1/48th scale, of 'fighter' to 'medium sized' aircraft, or around 20, maybe more, 1/32nd scale 'fighter size' aircraft. To have cases for this many would cost a considerable amount, whereas the cabinet ranges in price, depending on source, between £124 and £165 - approximately $200 to $266 US.
A bit of an outlay in one go, but covers future needs, and a lot cheaper than a number of display cases.