This is actually the real image
It's up to you... There is one person who asks 1223.17, and he's selling 2
BTC. So if you want to buy right now, and you want to buy less than 2
BTC, a bid of 1223.17/BTC would suffice.
If you want to buy more than 2
BTC, you'll have to look at the next cheapest seller to: 1223.19 CAD$/BTC. At this price, you would be able to buy 2
BTC at 1223.17/BTC and 0.71621216 BTC at 1223.19/BTC.
So in total, you'd pay (2*1223.17) + (0.71621216*1223.19) + fee?, and you'd get 2.71621216 BTC.
Usually, you don't buy everything the seller has to offer, so you can also buy 0.5 BTC @ 1223.17 CAD$/BTC, and you'd get 0.5 BTC for (0.5*1223.17)+fee.
If you're not in a hurry, and hope the price will plummet a couple dollars over the weekend (it sometimes does), you can even make a little lower bid, for example 1200 CAD$/BTC, and hope over the next couple of days, the price gets lowered, and somebody is willing to sell you some BTC for this price.