You're going to want to let people use their own certs if you want to sell to financial institutions and the like And wildcard certificates imply sharing a pri

You're going to want to let people use their own certs if you want to sell to financial institutions and the like And wildcard certificates imply sharing a private key around which is terrible advice If you're a business spend the money on certificates, if the business pushes back ask them "how much is your data worth? How much will reputational harm cost us?" Lots of people suggest rolling your own CA but I bet most of the internal CAs out there are terribly secured and not audited.