This is a difficult question to really answer; I think that the cost of the product is a direct reflection of how much it takes to run the company that makes the application. EG, If you have a company with 25 employees and you need to pay them each $50,000CAD you've got some selling to do.
ListMessenger was developed mainly by me, Matt Simpson, with the help of programmers, individuals and PHP classes. I personally put roughly 500 hours getting to ListMessenger 1.0; however, all it cost me was time and some smaller expenses. So my cost to the consumer is justifiably less than it would cost a larger company.
Anyways, this could go on forever, so I'll just say... because I wanted to develop a high-quality, inexpensive solution for individuals and companies to use to manage their valid electronic mailing lists.