There are promotional events run by various exchanges (Binance, CDC..etc) to promote on-ramps. You need to be on the look-out for these opportunities. Generally, they waive the 3.5% credit card fee and coupled with the cash-back from your card, you can get stable-coins at a great rate.
I have maxed out my credit card a few times in a month to make a quick buck on the effective exchange rate. I was warned by my bank to not do it though or they will penalize me.