When you work out the actual cost, considering that time=money, and the minimum wage in Ontario is 17 cents a minute, it is usually cheaper to have the purchase delivered by Canada Post. Add in negotiation over time and place, and it also often is faster.
There are exceptions. If you are not in the work force, your time may be easier to come by than money.
And if the item is bulky or heavy, it may be very expensive to ship. Similar problems arise if the item is very valuable (gold coins) or fragile (glass or china).
But ask, the seller is not required to agree. And part of that is the time=money, she may not be able to find a convenient time.