Here's details on the 17.5% surcharge...
http://www.canada.com/vancouversun/news/editorial/story.html?id=a1aeb1ee-0289-4c57-8c3f-6a17b8c5aa07. What I do is take a cab from the airport to my hotel. Wait the 24hours on my plane ticket while I adjust to the timezone by sightseeing with the free shuttles to Grouse and Capilano (or use the hop on services). Then get the vehicle for my third day stay to Whistler or Victoria. By getting the vehicle from the nearby downtown rental agency, I also save money on drop off fees to another location.
Because your children are all under age 9... it's expected they will be in baby seats or boosters. That can add be additional $40 to your daily rental. Taxi and public transit are not required to have children in the those seats. With those additional costs for a multi-day stay. Some bring their seats and others will buy $20 booster seats upon arrival and then donate it.
The other evil is you need two cabs with 2 adults and 3 kids. That will cost you $70 alone between airport and Sutton. Sedans and SUV will keep the family together.... but it's about the same cost as two cabs. Breaking the family into two is preferred as the cab fleet is much larger and can pick you up faster than the sedans.
Some other location things to consider after you work out your child seating arrangements.
- My preferred rentals are done with Alamo and National. They have an office inside the cruise terminal for drop offs. A minivan??? you better book several months early. The cruise terminal fleet is very tiny and it's a quick sell out if you wait weeks before your arrival.
- Avis has a shuttle from their office to the cruise terminal. But they like watching you wait for the shuttle. I hate that.
- Hertz has an office three blocks to the cruise terminal. They like to watch you drag your luggage the three blocks.
- Budget and Thrifty make you take a taxi or walk