www.BusRates.com offers some operators including a couple that post prices online. A school bus is probably $400 for the day ("not including 10% gratuity") and some have a 5-hour rental for slightly less money.
OSC has group discounts, as will most places I suspect.
http://www.ontariosciencecentre.ca/g...ts/default.asp
=aw
Last edited by ALW; Feb 3, 2006 at 6:06 pm