For me your market segment looks small, but you can always try yourself, of course.
First of all, you need to setup your site (this is obvious, right) and make it visible on search engines (read about search engine optimization, SEO).
Now you need to setup proper order processing procedure on your site. Having paypal only is not the best idea for a variety of reasons. We use Avangate and Share-it services for handling orders. They process both credit cards, wire transfers, checks and paypal.
Next, communities (forums, newsgroups) were and remain to be the place to find customers. Spamming as making unsolicited posts is, of course, not a good idea, but if someone asks for a tool, and you know that your tool is the right one in this case, then why not reply and tell about your tool? Yes, there exists a category of inadequate people, who treat each such message as spam, but you have to live with this (keeping in mind, that the world is full of alternatively minded people).
If you have absolutely no budget, then unfortunately this is all you can do at the moment. Once you earn something, start using Google Adwords to promote your product. It does work. Next, highly-targeted advertising on different sites works as well.
I wouldn't expect high sales from product of your kind, and it's especially important to choose right pricing and licensing model.
And remember that when you sell a license, you sell not just code, but also support and promises for future. While end-user software is sold as is, developer tools and components usually require certain level of support. If you are not ready to provide it after the license is sold, - don't start charging money (better put it as freeware and earn by something else like custom services).