Cheapest option would be a giant cardboard box you have lying around. Followed by a grow tent. Both go up passively to around 45C which is fine for ABS. They are working well for the occasional abs print. If you want something more professional you can diy an enclosure, prusa has the step files for a version build of ikea lack tables on printables. Many similar lack versions online You could replace the acrylic side panels for anything you have in your garage to save costs. In the end you can modify any box to be your enclosure. Last but not least there are full acrylic enclosures out there, even in custom sizes. Those look great but will come at a price. Dont forget that any pla printed upgrades for your ender will soften and loose proper function. Also electronics should be moved outside to lengthen their lifetime.

They work decently. I've never had an issue printing ABS with my comgrow one (I can actually print it easier than petg).

Although I am in the process of converting an old oven into a heated build chamber.

What's your end game? I printed parts for my Voron on an older non-ender i3 clone. To do so I

• used an all metal hot end. Granted, that had been on the printer for years and might not have been absolutely necessary
• reprinted all my i3 clone's printed parts in ASA. This includes the thumbwheels for bed leveling and the cooling duct. The parts were PETG and were deforming. For example, the bed was going out of level between prints likely because the threads in the thumbwheels were melting. All my problems there went away with ASA
• taped together sections from multiple cardboard boxes to make the enclosure. Finding one big box would have required going to a hardware store and buying one. Cutting a few Amazon boxes together was much lower effort

The parts printed pretty well, but the printer started... getting flaky toward the end. I suspect it's because the electronics were still enclosed in the printer, which was then enclosed inside the cardboard. If I had to do it again, I would try to make a somewhat more complicated enclosure to keep the electronics out of it and/or relocate the electronics or add a fan to them.