I have 25 or so JD's working for me. Most of them came to work here because they got sick of being at law firms, hourly billing, asshole partners, etc. We also spend about $15M per year on litigation, though the lawyers we deal with actually try cases...litigators and patent lawyers are different breeds.
Here's a dirty little secret: a monkey could be a decent lawyer. I have a few apes here and as long as they do what they are told, we all make money.
If it won't harm your career, then go for it. I don't think you'll have a lot of doors throw themselves open because of a tier 3 school, but many times you can get ahead because of a collective body of knowledge you have amassed....and a law degree could be a part of that.
I do think you look at a career decision wrong when you say "I could make $200K if I did XYZ....". You really don't know what doors can open and what is out there. If you are always looking for a higher pay day then you're going to miss out on the REALLY big ones that come with the patient accumulation of knowledge and experience.
Good luck bor.