What should be considered in fixing the price of SaaS application?

It’s generally a supply vs demand question. You need to make sure most of your costs are covered, but usually the initial “ramp up” period takes a loss to gain long term membership early. Once you prove concept you can creep the cost up, especially if you introduced the price as a type of early bird special. If your product is good, and has “stickiness” you need to consider the short-term loss for a long-term gain. If you try to make all your money early, you might put-price yourself and be stuck with no customers.