Why the big price difference? Alside vs. Vista

I got a quote for Alside Ultramaxx for 10 windows at just over $700 per window. Another contractor gave me a quote for Vista at about half the cost. This includes everything they both state, removal/disposal of old windows and warranty. Is there really such a big difference? I looked at the websites and read the brochures, but I can't see where one should cost twice what the other costs. Also, are there any brands to look at or to avoid? The house is a one-story brick house about 30 years old with the orginal windows. thanks

I'm not all that familiar with the Vista line, but at $700 a pop that Alside window overpriced unless it is optioned out with triple pane/krypton, woodgrain, grids, etc.... Although even then, there are better choices out there.

Still overpriced at that number as HomeSealed says.

Thank you. I looked up Vista and there doesn't seem to be alot of info, the company is not as established as many of the others. I looked at both sample window and I can see where the Alside window construction and parts seem more durable. The company with the Alside, employs everyone involved in installation (no sub-contractors). The company offering the Vista, uses sub-contractors, but is in my town and has been in business for over 50 years. Both have great ratings with the BBB.
I called the company offering Alside and spoke to the owner and he wants to meet with me and look at the house and see what he can do. I am really leaning towards giving him a "no, thank you," unless he can knock the price down about $1500. In looking online, I see a company out-of-state that sends rep to house to measure and order and then gives clients instructions on how to install. Looks like the windows alone would cost between $300-400 each. Obviously, not geographically possible and I'm a disabled vet, so forget my doing any kind of installation. I can't even clean my own floors.
Am I right in thinking that these windows should be in the $500-550 range? Or, can anyone give me some other brands to consider? You mentioned better brands, but didn't spill the brand names. I am in the Middle Tennessee(Nashville) area. Thank you