my opinion? too high for those goats.
and ditto what everyone else said on get a dairy breed.
I've got a doe that I paid $250 for 3 years ago that milked over 2 gal a day last year. here in SW MO I've seen in-milk does at the 1-gal production level going for $250-275, already in milk. if the production numbers are higher, I've seen them up to $500. unproven bottle doelings from top producer does are going at $125-200, and I think $200 for a doeling is too high unless there are exceptional producers up the line at least 2 generations... you're going to have to feed that doeling for a year and a half or more before you see any milk from her... and before you find out what her production actually is. of course, if you're looking for top-quality papered goats, and intend to show, you could spend way more than these numbers, however if you're interested in production only, the goats you saw, IMHO, are too expensive and not the right breed besides.
if you're buying for hand milking, check the teat size on the mama, and on the doeling both... teats will enlarge, but if the doeling has tiny nubs, she is more likely to have tiny teats... if she's got fingerling teats, she's more likely to have handlebar teats when she's milking.
My experience with nigi's is that they do not produce as much milk for their feed as my la manchas do, but they're quite comparable with my kinder, pound-for-pound. but milking mouse teats is not fun. I like them, personally, but I'm replacing all but 2 of them with full sized goats. those two have wormed their way into my affection, so they're staying.
BTW, if you're looking at breeding your does, and eating the bucks they produce, you can get a boer or kiko buck, or a buckling, or borrow one for breeding. your kids will be heavier, and will grow fast on the milk of their dairy moms. of course then you'll end up with some 1/2-1/2 doelings too and they may not milk as well as their mothers.
we breed our top producing dairy does to a dairy buck from a top producing dam, in hopes of more top producing doelings. we breed our lesser producing does to a boer buck in hopes of producing meat bucklings. most of the cross doelings we'll sell or go to the meat market as well.