A full application cycle usually runs 5,000 to 10,000 dollars or more once everything adds up. The AMCAS primary application is about 175 dollars for your first school plus roughly 47 dollars for each additional school. Secondary essays run about 25 to 100 dollars each, and then there is the MCAT and any prep you buy on top.
The biggest money-saver by far is the AAMC Fee Assistance Program. If your family income qualifies, it can cut the MCAT registration fee, give you free official prep, provide a free MSAR subscription, and waive AMCAS fees for up to about 20 schools, which alone is worth well over a thousand dollars. Apply for it before you register for anything, because the benefits are not retroactive. Virtual interviews have also removed most of the old travel costs, which used to be one of the largest line items.