My plans for this year will get me to 87,000 miles.
I would need a mileage run of 13K to get to ExPlat.

I have a personal trip Lim-Mia in december for which I am using miles. I could buy a ticket instead and get 5,000 miles mores at a cost of about $600 (plus a fee of $100 to get the miles back to my account). An maybe from Miami I could do a one day mileage run for the other 8,000 miles.

Questions:
Would it be worth spending 1,200 to 1,500 to get ExPlat? Or it is better to save that and stay Platinum.
Any MR sugestions from miami for 8K miles (providing it makes sense to change my award ticket to a paid ticket for $700)
I live in Lima. Any MR sugestions for the 13K miles needed?

Tks