As a fellow bootstrapped founder, you don't have to worry about drowning in support requests. Simply offer two pricing models, a $10-20/month without support (just work once on a good FAQ that answers the majority of questions), and a bigger $49-$69/month plan that comes with email support. Just because you're offering email support does not mean you're going to get lots of emails, you will be surprised how much a good FAQ reduces support emails.