Long Term Game Plan: Laser on a Budget

I’m an indian male with medium to fine body hair growth and medium dark skin tone.

I’m a first timer, though i have gone on consults. With so many people trying to ‘sell’ you on their services, it’s hard to tell the truth from wishful marketing.

My priority is back and shoulders, but would eventually like to laser chest and abdomen because i’m starting to get grey body hair and i know once it goes grey, it won’t respond to laser.

If i were to spread my chest/ab area out over a couple years, would it still be effective?

Instead of 10 sessions at once, doing 2 sessions per winter for 5 years assuming i pay attention to my hair growth cycles.

Thanks for your input and help.