graphics card upgrade

I'm currently running Resolve 15 free version and in the process of purchasing the Resolve 17 Studio version. I would like to do some computer upgrades and want to know if I will see much benefit. I typically only do real estate videos that are 2-4min rendered length, with color corrections, some motion text (sometimes Fusion created), and simple cross-fades between clips, with the occassional stablization needed for a few clips. We have recently started filming in 60fps at 1080p to slow down and create smoother motion and I'm having issues getting the clips to playback in Davinci Resolve 15 at the native 60fps rate, but Windows media player plays the raw files at native rate with no issues.

My current computer is:
Windows 10
Ryzen AMD 7, 1700-8core, 3.GHz
32GB RAM
NVIDIA GeForce 1060 6GB GPU

I'm on a tight budget and wanted to know if I would see any noticeable improvement by adding a second NVIDIA GeForce 1060 6GB GPU (after upgrading to Resolve Studio version), or should I replace it with something better? If you recommend a different single GPU, what recommendations do you have? My GPU budget is $250 or less. If additional RAM would be beneficial, I can add that as it's not too expensive.

Thank you for any advice.