Once you get your tracking number you call UPS and tell them you want to broker it yourself. They will then get your paperwork ready, and call you so you can pick up the papers. You get the papers and go to Canada Customs and duty, and they check your papers and chrge you duty and tax on your items, depending on where they're made. You pay and they stamp your papers, and then you go back to UPS and pick up your parcel.
In winnipeg the two places, UPS office, and Canada Customs are literally 5 minutes apart from each other, it may be different in your area. So, around here, it's a small inconvinience to pay for a large savings.
This method works for anything and everything. So you can do it for big ticket items and it will be cheaper.
Although the place you're buying from states that it only ships with UPS, you have nothing to lose if you ask if they'll ship it USPS. You're much better off receiving things through Canada Post, because they won't overcharge you on anything and is sometimes faster than the big companies.
UPS is a big hassle, go with USPS whenever possible.