I’ve been happy with my Dasking X3 rip off from Amazon.
DASKING Detachable Resistance... https://www.amazon.com/dp/B09GVBG878?ref=ppx_pop_mob_ap_share
I use the original X3 bar for my workouts and I don't regret my purchase. I respect the need to turn a profit and the fact that Dr. J has done a lot of good by popularizing heavy band/OSTF workouts.
I also note that the price point for the X3 leads to a lot of skepticism in other weightlifting communities (check out BBF) and probably prices out potential customers who would do these workouts if the X3 had a lower price point.
Accordingly, I'll note that you can get other bars for resistance bands (22" -> https://www.ebay.com/itm/294733269521; 30" -> https://www.amazon.com/DASKING-Detachable-Resistance-Workout-Exercise/dp/B09GVBG878) that use clips instead of the X3 hooks. If I couldn't afford an X3, I'd use something like that, and I'd probably get a pair of climbing carabiners if I were using truly heavy bands.