I know its a lot but I do wedding photography and everything is backed up 3 times for at least two years
Are you using any Raid setup?
Raid 5 or 6 are gonna save you a lot of space. Then you don't need 2 extra backup copies of every photo.
You could also invest in a NAS server.
since you have a business and require a lot of storage capacity a NAS server might be a great investment.
It's more professional in my opinion.