I did this last year at about $900. So, $600 was typical redeemable miles at a half cent a piece. That left about $400 for Diamond.
This was cheap to me as I had spent 50-60 nights but all on bought points, so I did not have many qualifiying points and not enough nights for Diamond.
This year, I have finished 70 nights for 'real' diamond. With the various credit cards, suite upgrades, and lounge pass, the year has been very, very good. We probably spent 24 nights in IC suites, one way or another.
I really can't tell you which upgrades and perks were Diamond and which were Ambassador, but the result is I got everything that they had to offer.
An extra $400 is paid for with a single 4 night upgrade, and another 4-5 breakfasts for 2, and not having to book unnecessary nights to get status.