Advice needed on an ATV for plowing snow

Hey everyone,

The wife and I just bought a house in the mountains of Colorado at 9000 feet. Our driveway is roughly 350 feet, and 2 sections hit a 20 degree incline.

I'm looking at picking up a Honda Foreman with a plow for snow removal this winter. However when I checked online and at the local dealer they're quoting $10,000 for a rancher with a KFI plow which seems incredibly high to me.

I was shopping around and found I can get a Kolpin plow setup for around $1000 and I'm happy to install it myself, but my questions for you are:

1) Whats a reasonable price to pay for a new Foreman or similar? (Looked at used but can't find a good deal in my area)

2) What do you think is a strong enough quad for plowing snow? I wanted the 520 but the dealership assured me the Rancher 420 would be enough.

3) Any other plow recommendations or feedback on the Kolpin plow?

Thanks everyone