I had the same questions about pricing. *Market value* by KBB and Edmunds was quite what I was looking for, but I ran across these links which have actual prices. Hopefully these will be helpful:
http://www.pricehub.com/price/Lexus/SC300
http://www.pricehub.com/price/Lexus/SC400
These are the actual prices people have paid, not estimates from KBB. Sorry, I don't think any of the prices are in Canadian dollars, they are all USD.