Madison Reed sits in an interesting spot: it's a salon-quality permanent color you apply at home. So the real question for gray roots isn't whether it works - it's how much it saves you over a full year versus booking the salon.
The cost over a year
At a 4-week cadence you're doing about 13 touch-ups a year. A Madison Reed Root Perfection kit is roughly $38 for two applications, so about $19 a touch-up, or ~$247 a year. A $95 salon visit with a 20% tip is about $114 each time - around $1,482 a year. That's roughly $1,235 saved annually, close to 83%.
Where the salon still wins
The salon buys you a colorist's eye, full-head application, and zero mess. If you have very resistant grays, want a color change, or simply hate doing it yourself, that premium can be worth it. For routine root maintenance between bigger appointments, though, the at-home kit is hard to beat on price.
Stretching it further
Many people split the difference: a couple of full salon visits a year plus at-home kits for the in-between roots. Keeping a temporary root concealer on hand also buys you an extra week or two before each touch-up, lowering your total color spend even more.