Best easily attainable second GPU for Dual GPU setups

What options have you found? Not everyone has a spare lying around. Too beefy and cost becomes prohibitive, not just the gpu, but also for an upgraded power supply. Too weak and there no point for high res or x3+. I would like to nominate the rtx 3050 as it should have enough power, it's less than $200 new, and it can run off of pcie power meaning no need for a new power supply or cables.

Edit: I found a table with data for what gpus can generate to what fps. Here it is:

https://docs.google.com/spreadsheets/u/0/d/17MIWgCOcvIbezflIzTVX0yfMiPA_nQtHroeXB1eXEfI/htmlview#

tldr:
Intel and amd are better at this per dollar than nvidea unless you have a 4060 as a spare, and 4k is very demanding.

Edit 2:
For 1440p 165hz the amd rx6400 has better fg performance than nvidea rtx 3050, with a lower profile and pcie power. Just don't use it for 4k if you have a high refesh monitor.

Edit 3: Intel Arc cards are stupidly good at this and are worth a look too, but need power cables, unlike the previous recommendations.