Why can I only buy $300 on Coinbase?

I'm puzzled about the purchase limit on Coinbase. Why am I restricted to buying only $300? Is it because I'm a new user or does it have something to do with my verification status? I've seen others able to make larger purchases without any issues. Could it be due to my bank or payment method? Is there a way to increase this limit? I'm interested in investing more but this restriction is hindering my ability to do so. Could you please explain the reasons behind this limit and suggest any possible solutions?