90 Regal Limited hard to stop!
 

My wife's Regal (90,000 mi) is hard to stop. I seldom drive it, and after buying a new model I think her car needs brake help. I removed the vacuum line from the booster and tried to drive it, it took every bit of my leg pressure to get it to stop from a slow roll! I replaced the disc pads when it had about 50,000 miles, odometer hasn't worked for 15 years, I am guessing she only drives about 3,000 miles a year.
How can I improve the stopping without spending a lot of cash?