I've read a lot of success stories from people having healed from a herniated disc with cold laser (lllt). There are even cases that people were so bad that they needed surgery and got treated with success with cold laser instead. Even a friend of mine got treated with success by a neurosurgeon with cold laser. Cost: about 50 euros per session and needed 10 sessions. The doctor even suggests taking an MRI before and after the treatment and see how much the disc herniation got smaller. There are even physiotherapists using cold lasers.
I've bought a cold laser machine for about 200 euros with 0 results. Be careful, even class 3B laser machines do not penetrate deep into the body and do nothing internally.
Professionals use class 4 lasers, which can reach even 30W of power consumption for some nanoseconds in order not to burn tissue but penetrate deeply. They cost about 2.000-10.000 euros. My machine has a continuous output, but of only 610mW.
There are cheaper LED (not laser) devices sold on Amazon which are very powerful (about 3W) and have many good critics. They cost about 150-200 euros.