Definitly bigger then 2 inches, I'd say 3-4 inches which is a healthy selling size. The one I got was about 1.75 inches, now that's small! Anyways, good looking Sen, hope he gets big for you!
Pretty quick, they grow quite fast when young. With a good diet yours should be growing at about an inch a month. My delhizi has really shot up though, went from 3 inches to 6 inches in 2 months.