T bone, most retailers will be happy to ship the firearm to you, if you don't mind paying by CC over the phone. Also, if you buy from a retailer in Alberta, you don't pay provincial sales tax.
But buying over the counter and taking it straight home is sometimes more than worth it.
Be careful when buying folding stocks from the US. Some came from military/police G36's and were formerly capable of FA fire and probably aren't legal here in Canada. Other than that, you're importing a hunk of plastic.
To find deals on stocks and other parts, check the E&E here and hkpro.com forums obsessively. wolverinesupplies.com also has well priced HK guns and parts and excellent service.