I think you are unlikely to be able to find low transaction fees at this time on any exchange, because fees on ETH are global.  you can find gas fee here .

Indeed, the current problem with Ethereum is about transaction fees that are very large.  Small transactions will only reduce the investment so much to pay the fees.  Many people choose BNB and Solana for small investments so they don't spend a lot on transaction fees.  Even though if you buy it directly from the exchange, it might save some costs.  Even though it is not recommended, it is still better than having to bear larger fees.  Because that's the case, leave your ETH assets as they are.  If you want to invest again, first see how much gas fee so that you find the best moment to reduce costs.  Or investing in BNB and Solana isn't too bad for trying.  My advice, if your transaction is small, just buy on a good exchange and try trading.  It will give you new flavor.