Ended up making something similar but with the ability to compress the fork as well. If you have any access to a welder I think making something would be the better option. That does not look like $45 in parts to me. I will try to get a picture later.
I made one for next to nothing, and it works fine. Not fancy, but it gets the job done for me.
I used a 2x4 and cut a hole in it with a large hole saw. Drill two holes in the sides for screws to go through and it's pretty much done. I sprayed it with clear to help minimize potential sawdust contamination, and I'm very careful when using it to make sure that no sawdust falls into the forks. So far I've used it twice without issue. I put one end under a vice on my workbench, and press the other end down until I can lock the spring down.