Always tricky!
Pricing formula
As a rule of thumb do a rough calculation of how long you think each stage of the project will take then add 20% for safety and another 15% for admin and communication.
There isn’t a formula sometimes you have to know how much the project will cost you so you aren’t operating at a loss, then throw a price at it
If you have a well defined offer:
1/4 or 1/3rd value of promise
If you haven’t done it before.
My policy is if you have less experience, treat it as being paid to learn and go cheaper.
Don’t try to charge high ticket prices if you aren’t confident of the results.
Long term relationships are more important than a quick buck.
Pricing Risks
The honest answer is if you’re doing a project which involves something you haven’t done before it’s a risk.
You have to make a best guess.
Sometimes you’re going to lose because it took more than you thought to provide a result.
But now you know how to do it next time.
Your estimates will get a lot more accurate to the point where when someone approaches you with a problem you know how to solve it and you know how long it’ll take to solve it. with more and more experience it’ll get easier to provide an accurate calculation.