Where can I find a cheap 500+ GB HDD?

So basically i've been finalizing and perfecting my perfect build for 2 months now. I was finally going to order this week, only to find out that I can't get a HDD anywhere, unless I want to pay 3x the price. My original build was an i5 2500k, HD6870 and a 1TB WD CB HDD that was only $70. I am a student on a tight budget, I can't afford to pay 2x to 3x what it is online at my local stores, being that EVERYWHERE online is out of stock. I am in Canada, so I don't have access to Frys or anything. All I really have in my City is Memory Express (memoryexpress.com) and ordering online. Someone please help, or 2 months of anticipation will be thrown out as I cannot build without a HDD.