Considered it for elbow tendonitis, but ended up electing for shockwave therapy (3 sessions), which worked out cheaper and didn't involve any time off training, although was pretty uncomfortable. Didn't totally work, but one year later seem better able to manage the discomfort with theraband exercises, avoiding the worst weight exercises and adequate rest.
I think you also ought to consider which joint you mare considering it for, as when i looked into it, not all joints are equally suitable for PRP.