If there's options it seems that it isn't really a proper tradition!
My dad has clearly failed, unless he will go for the 60th anniversary in 19 years' time!
We certainly don't have the money for it as DH hasn't found consistent work yet, but I had to make sure I told him no, as I know he would buy a ring if he thought it was tradition!
Luckily, he thought 10 years like me, and even then I really don't mind either way.
Also, my wedding and engagement rings are an unusual design and a third ring won't fit in with them, so that's another reason not to bother.
And I still think it is premature after less than a year of marriage, even if we do have a child.
But as I said, each to their own!