The theme and lighting is for a very small, specific genre where not many people I’d assume would be buying. There are some annoying invisible walls but the affects, especially spinning, are really cool. I, if wanting this very specific thing, would buy it for around 1k un-scripted and 2k scripted. (I’m also very stingy with robux so).
Considering you’re going to use this yourself, and the detail on the build is really good, I’d say something like 5000-10k Robux. You clearly put effort into the build and I think right around those amounts is good.
I’ve said before regarding pricing out complete maps, and typically why nobody buys them here:
Instead, I think this would make for a great portfolio piece 
I’m not really a huge fan of the bright neon pink colours you used. Trying changing some things to purple/violet. I love the moving spaceships above though. If you are going to sell this, your probably not going to get a buyer like what @Aotrou mentioned. I would price this map around 4000 robux. I would rate it a 7/10.
Great work!
Design looks really cool. I felt like I was in an underground galaxy for some reason. The spinning thing in the middle is cool too.
6k-8k robuxs
I personally don’t like the pink it hurts my eyes, but honestly I would give it a 7/10.