Handscraped hardwood flooring should not cause any problems with the furniture. It just means the planks were given a lot of character markings by manually scraping the planks before the staining and factory finish was applied. We have Mannington's Heritage Hickory Plank and love it! We stapled it down over 3/4" plywood. There are a lot of hardwood flooring manufacturers offering handscraped wood flooring today. Here is a link that might be useful: Installing Mannington Wood Flooring Heritage Hickory Plank

How is the wood fastened to the subfloor? Nailed? Glued? Floating? There are certain cases where to properly fix a few problem boards requires taking out the entire row. Now i am just speculating at this point. But minor to you may seem minor but there could be a lot more work involved. Especially being a prefinished product. Feather patching is expensive no matter your location. It requires skill to make it look seemless / flawless. On the other hand you might have just gotten a bad quote. I would call the guy and ask him to run through how the work will cost this much. Get specifics. That way you will know what he plans to do then if you wanted you could grab another quote and compare prices with an expected knowledge of the job. Also if you got a quote from a GC chances are hes gonna sub that out and upcharge what his sub is costing him and pass the bill onto you.

I am not an expert, but just a DIY guy, who has layed some wood and tile flooring myself a few times. Here are some of my thoughts. In your first paragraph you said you wanted to get an idea of the cost to extend the wood...well regarding that thought, I would hestitate to replace the carpet with wood if you were trying to make it match the existing wood. I think making it match would be next to impossible, unless you sanded it all, and then restained/refinished it all or if you could find wood that was a good match as far as color and grain patterns. Even if you could find something that "matched" (color/grain), it might still look visually unmatched after it is layed. So if you don't put in wood that is attempting to match the existing, then I think it needs to be obviously different. Different in color and contrasting dark/light shades. I personally think that whether it is cork or wood, as long as it obvious that you are "not" trying to make it match, then I think it would be fine. Such as if you were trying to find something to go with a traditional golden colored, oak flooring, I think a blond wood like natural maple or natural hickory would look good, or something darker like a chocolate color. Cork might actually look better (in a contrasting color), since it would be obvious that you were not trying to match the existing wood, in the same way carpet is obviously not trying to match the wood. Might also consider tile, I've seen some nice tile/wood combo floors before. But I would need to reserve final judgement until I had some samples in my hands to hold next to the existing flooring, to see what it looks like. There are many online flooring stores that provide free or close to free samples. As far as your height differences, one thing I've read is that cork flooring needs a level subfloor just as much or more as regular wood flooring. Beyond that, I'm not the best guy to advise on this.

We have cork (glue-down tiles) next to pavers. Although there wasn't much of a level change, we still had to use a trim strip for the transition. I wasn't a big fan of the transition strip, but it was a cost of doing business. That is the one -- ONE -- advantage of the wall-to-wall carpet the cork replaced: no need for a trim strip. If you ignore the Poang chair in the photo (I was selling it on CL) you'll see our transition from the pavers to the cork. We stained the oak strip to match the pavers as much as possible (it doesn't look that red IRL). I would think in your case, you would stain it to match the hardwood.