The guys are telling you right. For the seller it would cost him more to ship than the parts are worth. Therefore, you (a local buyer) have the advantage.
I'd offer him $75, let him reply with $125 and then meet in the middle. If he says $500, then walk away and call him back in 3 weeks.
When you get home you sort out what you can reasonably use. Then pile like-sized cutting bits into 5-10 piece "lots" and sell it on Ebay for (starting) $20 per lot. You should be able to sell the over-size and under-size bits for enough to recoup your initial outlay, and be able to keep the pieces that you can really use for your efforts.
If you'll look at Ebay for cutting bits, the hottest selling items are the "lot" groups of cutting bits. Especially note in the ad if the bits are marked USA and people will go crazy.
All these statements assume that Canadian post has something akin to the USPS "Priority Box" that is a fixed rate shipping no matter the weight. Good luck.