You can't put a cost on it. It's going to be a constant effort until you get where you want to be. Definitely be careful of a set one time fee to get you ranked.
550k searches monthly.
If you're page 1, the traffic would be incredible and the amount of money you'll make is huge (1k or even 2k, won't get you there). Especially with a brand new site, no backlinks, no pages indexed, and very little unique content.
(The top 10 have lots of domain age, lots of page rank, lots of backlinks, but not too much on page SEO) (Thanks MS).
I'd expect minimum $500-1,000 monthly, and that's wholesale pricing. And I'd also expect 6+ months of constant SEO pressure. Minumum. And that's just for the first page. This is a national market. If you could get first page for a few thousand, someone would have already done it.
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Don't get me wrong, I'm not saying don't go for it. Do it. But expect to invest a lot of time/money, and don't expect immediate results.