It absolutely is. My latest bass is the most expensive I have ever bought, previously something held by my Maruszczyk elwood. The thing that helped me to justify paying that much on the bass is not just that I fell in love with the bass (although I already did in 2017), but also the support I got from the luthier on a completely different bass that I got second hand on here, something that I would have had no issues if he couldn't help me with - he wasn't making anything from it, but he cared because it was one of his.
And I know that if I had trouble with that bass, he would help with it. And there aren't any troubles,
When you start customising the prices can go up a bit.
The difference there is you get a bit more customisation. My Elwood has an Ibanez neck profile. I couldn't get that from an off the shelf jazz bass. However, as the costs go up you start getting closer to the other custom luthiers and then you do get more options.
It is optional, mine doesn't have one of those, just a M logo.