Supports are the bane of all 3D prints. I think you should be able to print this tray completely upside down without supports. This can cause rougher surfaces (primarily at the highest point) depending on printer capability and settings but shouldn't be more than a 30-60 second sand job at most. You should also be able to print this sideways with sparser supports but a support interface. This would reduce sanding even further if not completely eliminate the need for it.
If you want to cut the print, cut a side panel off instead of cutting it in half. Put grooves in the side panel if you want it to be sturdier and easier to put together.
A quarter spool of filament per print is a lot. From the uploaded images, infill looks like about 80% which I think is the default setting in a lot of printing software. I'm betting infill could be reduced to 50% without significant structural integrity loss. And if any of the above suggestions work, you should be able to print without a raft since I think it's only being done because of the angled print?
Resin printers are also semi-affordable now. Printing this should be much cleaner and I think easier if you happen to have one.
This post is over two years old and I have changed my methods a bit. There are other posts with some details elsewhere.
Supports: I have minimized support impact on the print quality by printing it face up at a 45 degree angle. This only puts supports on the bottom where the finish doesn't matter.
Orientation: It CAN be printed upside down but I found the tunnel where the chips sit to be esthetically nasty. Sanding makes it worse as all the gloss is removed from the print. It is functionally fine but it looks bad. So I have decided after trying all the variations to print it at the face up 45 degree angle. The tunnels are nicer and need no sanding. The supports kinda just snap off leaving little to no marks. I usually run over the bottom corners with a deburring tool and that is all the finish I do. The 45 degree angle also makes for the best tunnel surface result.
Infill: I printed almost all of the trays I have made between 20% and 40% infill. I like 40% best for weight. It ways about the same as an injection molded tray of the same geometry. I mostly do 25% now for a tradeoff in printing speed and finish quality, sacrificing a little bit on weight parity with injected molded racks. I also don't use a raft, ever, anymore. I have solved bed adhesion issues in other ways.
Partial prints: If you want to do a rack the fastest and don't care about visual quality, print it in two pieces with the sides against the bed, no supports, 20% infill, and glue them together. It works. I have done it. If you do it with two different colors it looks good as well since there is an obvious color change rather than gross seam. You need to clean up the glued edges a little bit before gluing them together for a better fit and cleaner finished product. I have even done it with four parts for a striped look. I like it quite a bit and am deciding if I want to make more for myself this way.
Resin printers: There are no inexpensive resin printers that will print something this size, yet. There are a few commercially available ones but they are quite expensive. Also, resin isn't quite as indestructible as PLA or PETG but is catching up if you use some of the more expensive resins. Resin will get there but isn't there yet.