i dont think they charge anything @ babyslings&carriers.
they have quite a variety of slings & carriers to choose from.... thu DH & myself has set our eyes on a particular carrier, we wanted 2 try... they were quite helpful...
I saw a Tula standard size sample at Mothercare Harbourfront. Baby Slings and Carriers website states that there is a $20 fitting fee, redeemable upon purchase of a carrier.
Do note that for Tula, a separate infant insert is needed for babies under 4 months old. Smaller size babies may need the insert till 6 to 8 months old, which may be warm for baby and troublesome to use.