Not sure what to do about getting a setup.

I have a TRBX304. I think I paid around $400 for it I was unhappy with the action, so I watched several videos about doing a setup (figured it would be good to know how to do), and gave it a try. Unfortunately, it was worse off than before.

So, I decided to pay for a setup, as I didn't want to have my crappy effort get in the way of me practicing. I took it to Guitar Center and paid around $100 for it. It was barely better than my attempt. I should have read reviews first - apparently GC doesn't have a great reputation for bass setups. I think they just did some minor adjustments from my terrible attempt..not a full on setup.

Anyway, I found some local professionals that are very well reviewed..but they charge quite a bit more. I feel weird paying close to $200 to setup a $400 bass (would be near $300 total at this point..)

I could just try again, but I just am not confident...I think the nut holds the strings too low and it's more than I can comfortably fix on my own.

I'm in the Baltimore-DC area. Any suggestions? Would a pro luthier be overkill for a $400 bass?