The AIS cost is for up to 3 systems, I don’t know what sandboxie is. So if you have more than one system it will possibly work out cheaper.

But in all honesty you can’t compare the two on price as they are completely different applications and AIS offer more functionality/security and it included the full sandbox function in the avast Pro that is part of the AIS package.

The AIS license is for a year, you can increase the duration (2 or 3 years) and that should also slightly reduce the cost per item per year.