I am not an expert but have been following the projector threads as my projector is 12 years old and at some point will need to be upgraded. There are various technology points that are important. In my case HDMI 1.3 was fairly new but has allowed me to keep using the projector. I would suggest that currently 4k and HDR10, and 18GB HDMI are a new level of technology that should be considered the minimum mandatory going forward.
The current consensus seems to be that the NX5 or the 295ES are probably the best bang for the buck if they have enough lumens and fit your room constraints. In your case I see no issues with the NX5 and they seem to be close to your price point if you look around and are patient. Given that you keep your projectors for a long time I would think that is an excellent choice.
From what I have read, not seen, I would hesitate about making the trade off to solid state and DLP. Before I get flamed, my projector is a DLP, my next projector will likely be a DLP. However, the current generation of XPR DLP machines with a color wheel tend to have RBE. In my opinion this is a fundamental limitation of the XPR processing. This along with the inherent black level compromise make these projectors less desirable unless the solid state technology is very important to you.