There's a circulator bus that goes between National Harbor, MGM, and the outlets. It's $5 a day or free if you stay at the Gaylord. You can pay cash to the driver or prepay using the Reston Limo app (but I've found it easier to pay cash). I highly recommend the use of this bus.
Yes there's a shuttle bus that takes you to National Harbour (MGM is just around here) from King St, Old Station, Tanger Mall and it costs $2.
Yes, not sure how it runs or costs.
Yes not sure on price
Not sure have to call MGM to be sure
Yes not sure how often it run
Yes there is a metro bus from king st old station to national harbour which enroutes tanger mall and mgm. Basic fare is 2$. It is frequented every half an hour till midnight
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