That's 2 days of median disposable income.

For comparison:

San Francisco, U.S. - Disposable income after rent: $4,710

Zurich, Switzerland - Disposable income after rent: $4,626

Chicago, U.S. - Disposable income after rent: $3,298

Boston, U.S. - Disposable income after rent: $3,188

New York City, U.S. - Disposable income after rent: $3,157

Sydney, Australia - Disposable income after rent: $2,615

Melbourne, Australia - Disposable income after rent: $2,485

Oslo, Norway - Disposable income after rent: $2,342

Copenhagen, Denmark - Disposable income after rent: $2,285

Wellington, New Zealand - Disposable income after rent: $2,075

Depending on your list and method, New York could be 44th on global purchasing power index:

https://www.numbeo.com/quality-of-life/rankings.jsp?title=20...

Or 15th:

https://defence.pk/pdf/attachments/screen-shot-2019-11-27-at...

Anyway, "no other major metro area has that kind of disposable income" seems inaccurate.