The RX 5500 was only sold as an OEM part in prebuilt systems, so you will only ever find them on used markets. You should just look for RX 5500 XT since those were sold at retail.
Equivalent cards to the 5500 XT are the RX 580 or 590, RX 6500 XT, GTX 980, GTX 1060 6GB, and the GTX 1650 Super.
The RX 6500 XT will be slower in some games because of it's x4 PCIe interface and the GTX 1650 Super is hard to find without ridiculous prices.
If you have a larger budget you should look more for something equivalent to or slightly better than a GTX 1660 Super. The newest cards that are as fast or faster would be an RTX 3050 or a faster RTX 2060. You should be fine to run even faster cards like the RTX 2070, 3060, RX 6600 or 6600 XT.
Any money spent on faster GPUs than the RX 6600 XT would be better spent upgrading your CPU, motherboard and ram.