If I achieve Platinum status using the Platinum Challenge route, am I then able to buy back Platinum after it expires as I have been able to buy back Gold in the past?
Yes, but it will cost more points (40k vs. 25k).
The good news is that if you complete a Platinum challenge in 2015, you get to keep your Platinum status until Feb 2017 even if you don't end the year with 75+ nights. After that, you will either need to hit the 75 night mark or pay 40k points to retain Platinum.
On point, bejacob. Thanks for stepping in with the solid answer!
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