I'll agree. Track clips will look rusty in about 12 hours after you ride the sled and the snow starts to melt. And after trailing in salt spray they'll look truly nasty! But it usually rubs right off and hurts nothing. So inspect them immediately after a good ride and see what they look like. If they really are pitted, the worst you'll do is sacrifice a set of hyfax, which likely need replacement when you put your new clips/track on anyway.
If you need to replace clips, yes you'll need a special tool to crimp them on properly...figure on $60 to $100 USD for the tool depending on what kind you buy. Dennis Kirk and all their competitors sell 'em. Free or cheap if you can borrow or rent one. Plus the cost of clips. Plus you'll need a cutoff wheel or angle grinder or some tool like that to score off the old ones. And you'll need some time on your hands as it takes a little while especially if you haven't done it before. But it's not too tough. As for whether you want to go through all that or replace the track depends on your money situation and whether the rest of the track is good enough for you.
You can likely buy a good replacement track for $300-ish (US dollars, not sure in Canada) even less if you buy a used one from Ebay, and then you can sell your old one on Ebay for $50 to $100 usually, even with rusty clips. But then there's the incidentals...it might be a good time to replace your axle bearings anyway with that many miles, and that requires track removal. Then you'll want new hyfax, and as long as the skid is out you might as well go through all the wheels/bearings/shocks and make sure they're good. So in the end, a $300 USD track replacement can turn into a $500+ project real quick, but it's all stuff your sled probably needs after 6K kms and you just don't know it yet. So the choice is yours, not the dealers.
After typing all that...I betcha don't need 'em. I recently replaced a track that had almost 12,000 KM's on it because it had some blisters forming in the rubber. But all the clips were perfectly fine and not one was ever replaced. The only reason I could see you needing new clips now is if someone let the hyfax wear through at some point in its life.