Waterbourne from what I recall was always more expensive wholesale and consequently retail in poly's.

Isn't oil based more durable though? I assume he is talking about the idea that the oil based will yellow a bit. And, will you see the two different floors right next to each other anyway?

How much more expensive is water-based versus oil-based that it results in $300 more for only 500 sq. ft. of flooring? That does seem pretty steep to me, especially considering that the time to do a floor with water-based is significantly less.

That being said, OP, around here the going rate is about $3/sq. ft. to refinish wood floors. At $2.60 a sq. ft. for water-based finish, it still seems like a good deal to me. But that depends on your market, of course.

I'll add that, as much as I prefer the look of oil- to water-based poly on wood floors, you should go with what matches the rest of the house.

The water based poly I chose requires a 24 hour wait (for drying/curing) and light sanding after two coats. So it would take two nonconsecutive days to do the recommended four coats of water based poly.

A 500sf floor would require 4-5 gallons of the water based poly I chose which is $50 per gallon retail. I think oil based ran around $30 per gallon but I don't know how much would have been required.

So will you have water based poly on both floors? Because oil based poly may continue to become more yellow. You should use the same type of poly on both floors if possible.

That comes out to 60 cents a square foot. I generally charge 30 cents more for a base level waterborne finish like Bona Mega, however I do use Mega all the time. If I had to order in a product special, account for waste, include full bottles, and pay for shipping, that could add to the price.

I believe water based costs more due to demand/supply. Flooring contractors prefer to use water based due to constant exposure to vapor fumes from oil based. Thus there is more demand for water based and less supply of it so the cost is more. When/if they do your floor with the oil based, you will notice what im talking about.

Oil leaves an amber hue changing the final color of the stain. That is another reason why flooring contractors like to use water based. The quality water based poly's are usually just as durable. The only difference between oil and water is the substrate that evaporates as the poly dries.

Water based also cures faster than poly, allowing more coats per day.

http://www.houzz.com/ideabooks/14998567/thumbs/water-based-vs-oil-based-polyurethane-floor-finish

There is no shortage of waterborne urethane so that's not the reason for the higher cost. Either it costs more to make, or people perceive that it offers a higher value and are willing to pay more. Considering that there's a lot of competition in the industry, I wager it's the former. If the markup was that big, a competitor would exploit it.

We have an entire Blog post that explains the difference, including cost and durability, between oil-based and waterborne polyurethane. These questions come up pretty often and the difference is simple; Oil-based is less expensive, and is more durable for a longer period of time, especially in high-traffic areas. The only time we recommend using a waterborne polyurethane is when the color of the stain or natural wood need to remain without an amber hue. Examples of this are with a Grey stained hardwood floor, or a natural maple hardwood, to ensure no "yellowing." The Couture Floor Company

For more information, click on the link to our Blog on "Oil vs Water polyurethane."

http://www.thecouturefloorcompany.com/oil-vs.-water-based-polyurethane-.html