You can buy some VEGAs, they are still very good and also currently pretty cheap.
Or some cheap RX 4xx/5xx they are very cheap, but ROI is still long with current prices.
You can try mine RYO, which is good with VEGAs and other 8GB AMDs, dev team is very skilled (dev team from XMR-STAK miner) and you can mine a lot of it now with expectation for better prices hopefully soon.