I sell B2C software with a subscription of 1.99€ per month. I have 7,000 active users. I get 5-10 emails per day max.
Before I charged money for my software, I was afraid of the overwhelming flood of customer support requests. Except they never came.
> even one short email enquiry would wipe out a dozen sales or more (if you put a monetary value your time)
Per email, yes, absolutely. Sometimes I take 20 minutes to answer a more complex email. But since I know that I don't receive more than 5-10 emails, I take the time and this person might recommend my software to other people, because of the great support.
An easy way to mitigate customer support is to have FAQs and lots of written texts on the website. Most people prefer to help themselves I think, because its faster.
Sometimes I wonder if this is a mentality thing. My customers are all Germans. Maybe US customers are faster to send a short email than browsing through FAQ.