Send Starburst an email with the Happs part numbers you are interested in. They will give you the price and whether they have them in stock. For comparison here are the prices I got from them earlier this week:
Competition joysticks are $15.00 each and in stock in black.
The standard pushbutton with horizontal microswitch (part# 58-91XX-L) is in stock in 8 different colors and sells for $2.00 each
56-5500-10T 2 1/4" trackball red translucent $115.00
55-0203-00 mount plate 2 1/4" black $20.00
49-0999-00 T-mold 3/4" black $.35/foot (in stock)
49-0999-10 T-mold 1 1/2" black $1.10/foot (minimum is 25 ft)
I believe they also stock more than Happ, but you may have to go to the shop to find out. Or send an email with the part info.
WRT shipping, I'd recommend USPS. UPS is notorious for extra brokerage fees, and I think FedEx has the same issue. But you should also assume that you will get charged the C$5 Canada Post handling fee plus duty, see
http://www.cbsa-asfc.gc.ca/import/courier/postal/ind_duty_free-e.html. But even with USPS shipping is not cheap, see the end of
http://pe.usps.gov/text/Imm/immicl/immiclcd_003.html, minium US$8 for a 1 pound package (with no tracking or receipt). I figure you have to be saving at least C$25 before taxes (assuming tax=duty) to make it worth it.