Why do you want to purchase a claim? For a place to camp? For a hobby? If it’s either of those two reasons, consider the much cheaper alternative of joining a prospecting club that already owns a bunch of claims.
Most people that ask this question with the intent to “make money” gold mining are about to make a whole bunch of money for other people (people that sell claims, lawyers, feds, companies that sell mining equipment, people that sell advice, etc...).
I love finding gold. Be careful!