Is that before or after your tax system gets a hold of you? I know in Ontario any service includes a size-able tax (GST, VAT, PST, LMNOP and whatever else they seem to come up with) to go along with it. I almost fell over a couple years back when I was charged an additional 6% recycling tax (on top of the 13% sales tax) on a DVD player I bought there for the family's cottage and that was on top of the already inflated price (at least by US price standards) of the DVD player itself. And while I'm on a rant whatever happened to the great prices for beer in Canada? Last summer I almost fell over when I went to buy a case of beer at the beer store and they wanted $42 before the 13% sales tax. Beer at the local bar had also climbed to $4.50 a pint and that was for Coors lite. Come to think of it at those rates $700 is looking pretty cheap for winterizing.
Comparing US and Canadian labor rates is going to be difficult. Regardless one sure way to get around them is to learn to do the work yourself. Winterizing isn't that difficult for most average guys/gals with moderate mechanical skills. There's also a ton of help here should you need it. I know I would be doing a lot less boating if I couldn't do this work myself. You'll also be very popular with your other boating friends that will no doubt want you to share your new found skill set with them.
I would concur with others on the gel work. Unless this is a big shop they're most likely subbing this work out and charging you to take the boat to another shop along with an uplift to make it worth their time. I know my local dealer does this. A lot of times you can call around or just ask someone at the dealer casually who they use for their repairs and they'll tell you. A good way to go about it would be to plainly ask "do you do your own gel coat work here or do you send it out?" If they say they send it out ask who they send it to.