I'm checking into pricing a domain name and wonder if the price gets higher once you have invested time into a website? Can you be extorted if your site gets big?
Yes, as the name becomes more valuable.
This was literally the first scummy practice on the mainstream internet. Buy it and register it at a low rate for as long as possible.
if you're concerned the cost will increase if you are sure the site will be popular and worth something, then lease the domain for 10 years when you get it at the low rate.