I'm new to the concept of a mileage run and I think it'd be fun to do one...not so much for the miles and status (I struggle to fly 25,000 miles a year), but simply to fly around for a couple of days.

I will probably be in Orlando in October for a convention and am looking at a 4day weekend after. In looking at different places to go (Vermont, Europe, among others), I decided to check prices to HKG.

Here's what I'm looking at:
IAH-MCO (10/10) 853 miles O fare
MCO-EWR-HKG (10/15 +1) 8998 miles W & B fares
HKG-EWR-IAH (10/19) 9475 miles B fares

I'd have one evening and 2 full days in Hong Kong. I've been there once, so I'd probably take pictures the entire time.

With tax, the price is $1574.63. I'm Silver Elite for CO OnePass, and I believe I get 50% bonus miles. So if my Aggie math is correct, I'll get 28,989 miles for a cost of $.054/mile.

This isn't too bad a deal, right?

That isn't too bad, but it's certainly not the best. The question is what does the MR do for you. Whatever benefit you see in doing a mileage run you have to ask if the benefit outweighs the costs. This MR will certainly help you maintain status -- you would only need roughly 6,000 miles in 6 months to retain status, and that can easily be done.

You've got plenty of time before October rolls around. Since you seem to be doing this for the adventure as much as the miles, why not check prices to far away place you have never been to? Only you know where that might be, but let me suggest DEL or ATH. Much as I enjoyed HKG, I'd much rather visit Greece or India than Hong Kong. But, I have not priced these out. I guess what I am saying is, What you found may be best, but don't stop looking.