Refers to the mildly-indignant answer that you snortingly "toss back" at a seemingly-impertinent clueless who naively asks why you don't "just buy your way out" of a moderately-inconvenient/difficult/unpleasant situation, his not being familiar with the enormous financial outlay that said "easy-solution" choice/action would entail.
Two typical/everyday examples of an astronomical-cost retort would be with regards to having a garage come and pick up your presently-non-drivable vehicle instead of having a friend help you tow/push it the few miles to the garage with another vehicle ("Yeah, **sure** I could --- for a nice HUNDRED-BUCKS TOWING-CHARGE!"), or if you presently have to turn your well-pump on and off manually because it's "on its last legs" and so you always have to be "right there and ready" to quickly turn the pump back off to avoid damage if it doesn't immediately start up when you power it on ("Oh, yeah --- new pumps are indeed available --- you got an extra THOUSAND BUCKS OR MORE JUSS LAYIN' AROUND to get one installed??!"). Never fails to shut the impudent inquisitor right up!