Web MVPs (landing page with a signup form) can be done easily from anywhere between $200-1000. Yes, I realize there's stuff like unbounce, but even with those, they still take a couple hours to set up and properly split test. If you've never done this before, you can easily burn through that very quickly, and even if you have done this before, and you're valuing your time as any good founder should, then you're burning through that value allotment very quickly.
As for the foreign quotes, I've taken over plenty of jobs where it was started by a foreign firm for a tenth of the cost of what US firms charge... quality is usually terrible, and the reason I took over is because they couldn't get it finished. It's occasionally been so bad that we had to scrap their entire project within 6 months.