do you happen to know what is the minimum requirement? and is the minimum requirement for "each" of spouse or joint amount together?
-Check this link:
https://www.uscis.gov/sites/default/files/ilink/docView/SLB/DATAOBJECTS/I_864P.pdf
If the beneficiary (foreign spouse) is employed in US, then his/her income can be used/counted for I-864 filing, otherwise if the beneficiary is employed outside US, then his/her income can not be used.