Like if there's a waiting list for years but you can pay to get in earlier (presumably to the detriment of everyone who has to wait)?
Under the framework of capitalism, no - it is not unethical. The incentives all around are all shit, and everyone is acting "ethically" in the sense that everyone involved in the transaction is doing the most "efficient" thing. The kind of doctor that gives priority to cash generally only takes cash payment anyways.
Being a martyr and doing individual consumption stuff does not change the fundamental relationship there.
It's just a result of capitalism. It's as ethical as the rest of it. Just recognize what you're doing and support changing the system.
I have a wealthy relative that is anti-single payer because "the US healthcare system is fine" who pays like thousands a month for access to an on-call private doctor that only takes a limited number of patients (less than 100, iirc) that they can see next day most of the time. Don't be like that.
