Swim Trainer?

After dutifully using the search function to read the thousands of posts about swim trainers, I am left with two questions:

  1. With limited access to the pool, will the purchase of a HALO2 benefit me significantly more than just using stretch cords?

  2. Can I build my own for < $100, using a flat bench, a set of power cords sourced locally, and one of the ‘templates’ available from the website.

Basically, the $500 that it’s going to cost me after shipping, duty, customs charges, etc. is bothering me a bit. well, ok - alot…