Re: PIA excess luggage
don't know about toronto to lahore, but lahore to toronto was Rs. 6500 per extra bag (given it was within it's 32 KG weight limit)...and this is from personal experience, in oct. 2008...
assuming its the same from toronto to lahore, u're looking @ around $100 i'd say...best bet would be to call up PIA and ask them directly :)