I’m not sure it is that easy or cheap to find a 3rd level schoolmaster to take lessons on! And if you do, you’re even less likely to find one that is available daily to meet your schedule, or even 3+ times a week-- unless you lease it.
I am an eventer who has both leased and owned in the past and am currently taking a break from ownership and doing lessons instead, and while there are lots of advantages (price for sure) it’s very different from either leasing or owning and I’m very aware that my lovely lesson horse is only “mine” for an hour at a time.