Thread: Is it possible to add varied prices depending on form fields?

Is it possible to add varied prices depending on form fields?

Sorry if the title is a little vague, I will try and explain a little better here.

I have a website that offers listings in multiple county's, and I can set these up as the categories. What I would like to do is charge a price depending on the number of categories they choose. Is this possible?

I am a competent PHP developer and have created a number of WordPress plugins before so getting my hands dirty is not a problem, I just want to make sure that it is possible and also how tricky it may be to do so.

Thanks to anyone who takes a look at this and even more thanks if you can provide me with any advice!

Cheers,
Tom.