I'm saying $500 for;
3 - 2x39W retro kits $450 ------- this one is tooo expensive ...
3 - super quiet computer fans $45 ---- you can go to grainger to purchase--
acrylic or glass lens $10
Wood I have it laying around from other projects
Misc hardware $10-20
The retro kits are the killer here. The bummer is that you just can't get the quality components cheap because they are in high demand now. T5s are good because of their effiency, skimp on anything and you lose that fast... Pretty soon it's just a straightened out PC