On average, these things last me 4+ years. Before these were always $20-$28, but their on sale for $14.14, so I just bought 2.
I’ve bought a couple others, from Wahl as well, and the gillette is my favorite.
I use the eneloop rechargeable batteries and these things last forever.
https://www.amazon.com/gp/product/B06XF3KHFM?