Discussion thread for disposable email services.
With a custom domain you can use self-hosted software and have unlimited aliases for very cheap. You will know if one address leaks and is used actively, but they can leak passively and pin down everything to that domain. Lower privacy, lower price, high skills.
With managed services you pay by usage, but can spread it around different services to make it harder to correlate. Higher privacy, higher prices, lower skills.
A mix of the two seems like a good idea. This is a solved issue for me, but I am not going into details, good luck.