Good luck Wayne.....I was in exactly the same position when I made master tier.
On Kiawah and St Andys, it was possible to shoot par or even better on a good day with some luck,
Other courses was very tough, especially on a few holes.
So what it boils down too, is keep challenging yourself (not necessarily having par as the goal) or you will need to upgrade.
I chose the upgrade route.....but ask the forum users first as it may save you dud upgrades.
In all fairness, I regretted not upgrading earlier as for me, the game became even better.....but I could not come to terms with the concept I would have to spend real money (next to no offers here) for something I would never own lol.
Good luck whichever route you take- both are still fun.