I made mine four years ago for about $300 USD, lets’s see what it would cost me today… Looks like it would cost me right around $200 to build it today.
I started with a 6 ton shop press at harbor freight for $65 (don’t forget your 20% off coupon).
https://www.harborfreight.com/6-ton-a-frame-bench-shop-press-1666.html
I got two 1" x 2.5" x 2.5" pieces of aluminum locally for $15 cut. This is 1" x 2.5" 6601 aluminum bar stock cut to 2.5".
Each plate has two cartridge heaters in it, so a total of four for $35. The holes were drilled in the side of the plates to accommodate them, as well as a third hole for the thermal probe that came withe PID controller.
I called in a favor from a friend to weld a piece of pipe to a square piece of steel. I then threaded three screw holes in the pipe to hold it to the press pin. The top plate had four holes drilled and tapped to hold this piece on to the top plate. You could probably make due with a pipe flange for $6.
https://www.lowes.com/pd/SteelTek-3-4-in-Silver-Galvanized-Steel-Structural-Pipe-Fitting-Floor-Flange/999930950
The bottom plate just sits on the arbor plate that came with the press.
Finally the cartridge heaters were controlled with a PID controller with a solid state relay two of these for a total of $80.
https://www.amazon.com/Inkbird-Temperature-Controllers-Thermostat-ITC-106VH/dp/B01N1ZUGUZ/ref=sr_1_2_sspa?dchild=1&keywords=inkbird+itc-100+pid+ssr&qid=1596575224&s=industrial&sr=1-2-spons&psc=1&spLa=ZW5jcnlwdGVkUXVhbGlmaWVyPUExT0s3Q1RKSjA5M0tIJmVuY3J5cHRlZElkPUEwMzcxMzgzMk1QNDZPOFNNWFZQQyZlbmNyeXB0ZWRBZElkPUEwMjMzNDQxNVBTNjQ5VzhQRFNYJndpZGdldE5hbWU9c3BfYXRmJmFjdGlvbj1jbGlja1JlZGlyZWN0JmRvTm90TG9nQ2xpY2s9dHJ1ZQ==
Of course I threw this all in a project box with a cord receptacle and a couple of switches to make it look more professional. For about $20 more.