You're right in that it isn't cheap compared to an open source editor that you can get for free. It is cheaper than other paid competitors though and we believe it is superior in many important ways. For example, it's the only one that can do both In-Place and Form based editing. It also cleans the HTML very well: Try pasting in from Google Docs, or Word, or any random HTML page (I like using Slashdot because it's a mess of nested tags). We also fix a bunch of issues to do with browser differences. I think you will also like our roadmap which includes many more features not available anywhere else. We have experience implementing many of the things in the roadmap already so they will be coming.
If you are looking for low cost, there are a lot of alternatives. One of the goals with SnapEditor is actually to make it for people who are willing to pay for their editor. This obviously benefits us (since we want to make profit) but we believe the needs of people who are willing to pay will be different from people who are not.
Do you have any paying customers yet?