Upgrade the projector or projector screen?

Hello Everyone!
 My Current setup: 
Epson 5030ub + Screen Innovations series 3 - solar white (1.3 gain) 100 inch diagonal.

I sit about 8 feet away from the screen and my HT setup is totally dark with grey walls. 

My goal is to upgrade the picture quality and I want to stay under or around $5k. 

My QUESTION: Should I upgrade to a Stewart Filmscreen StudioTek130 screen OR upgrade my Projector to a JVC DLA x790r or similar? 

What will make the biggest positive impact? 
The screen is more of a factor if you don’t have light control. Since you do, focus on the projector 📽 and getting one with the right throw distance for your room. 
I got to agree with just getting a whole new one.

I got the BenQ MH535FHD 1080P Home Theater Projector

I believe when I got it, it was like $650, now it's down to $550. I believe this is the site I found it on: https://www.officialtop5review.com/tv-theater-projectors/

For some reason their top recommendation came back not found so I just went with the second one.

Anyways, you can also just look on Amazon and find ones with good reviews that are at a lower price If that's too expensive. Good luck!
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