It's hard to recommend a GPU for an older system like this. The budget, PSU limitation, and the older platform limits what you can get. A used 1060 may be a solid option if you can find a decet used one. An RX580 could also work, but your power supply is likely borderline.

The above options are findable on a $100 budget, but not easy given how much GPU prices have gone up. You may have to settle for used. A 1660 or 1650 could also work used in your budget range.

If you want new, you are looking at a 1050 or 1050 Ti. Both are technically upgrades for the 460, but are not significant upgrades. The 1050 Ti is a better choice than the 1050 if you can fit it in your budget.

TLDR: 1660, 1060, or 1650 are all decent upgrades. Hard to find them in your price range. 1060 is probably the most likely to find in the $100 or lower range (likely refurbished and will need some hunting). If you want to avoid hunting for deals/refuribished/used options, the a 1050 is probably it. Maybe a 1050 Ti if you find a deal.

Disclaimer: Check for compatibility for the various cards and make sure your PSU has enough power to support them. I tried to base recommendations based on your 300W PSU and older motherboard/system.