Kevs,
A couple of things.
First, I'm not a pro photographer, but I have owned a business, and I was in sales for a number of years.
You've mentioned a few times being "annoyed". That's not useful or productive. It's just business. Those people likely have no idea what goes into a professional product.
You can either try to educate them, or blow them off. Sometimes one's a good decision, sometimes the other is. For people who didn't seem to be worth a lot of effort I had a few email templates that covered the common situations. 30 seconds or so of personalization and off it went. If I got a reasonable response then I'd spend more time. If not, a quick email thanking them for their interest but saying that we weren't the right vendor for them got them off my plate. Very little effort, no annoyance.
In a small business you have to realize that every customer isn't going to be right for you. Figuring that out early is important, "firing" a customer later (which I had to do a few times) is much more of a headache.