Need hi res images saved to smaller sizes

i have hi res images ( 57 ) at 8500 x 5500 @ 300dpi in landscape format and need to reduce to 3000x3000 and 540x540 both to 72dpi. don't think this can be automated in photoshop so probably needs to be done manually once to get to 3000 then can be automated after that as already in square format. example attached. need asap. another 57 to follow different angle so potential for same job again. client has no budget so price is important as is quality of work, apologies for that.
any questions just ask.