Here goes... from most to least bang for your buck (Disclaimer: in calculating "bang" I did not weigh in the probable inverse relationship between price and quality of reviews.)
Bookmonster "Name Before the Masses" tour
$50 gets you 22-31 book reviews. That's $2.27 per review, max.
My opinion: This is by far the cheapest place I've seen. It's tempting, but something smells fishy. There are a lot of broken links and a lot of sponsors at .blogspot.com. Nothing explicitly wrong with it, but something's off.
Orangeberry: "OpsMore60" plan
$290 gets you 60 book reviews. That's $4.83 per review.
My opinion: Well, not many people had nice things to say about Orangeberry at the Absolute Write Water Cooler. As a reviewer myself, I've been asked to review books that had a heck of a lot of 4 & 5 star Amazon reviews, all the same length, all original but somehow flat. Those books don't pan out. I've got a sneaking suspicion that services like this use a lot of fake pseudonyms. On the other hand, that's a lot of reviews for not much money. Is it worth a risk? Maybe.
Reading Addiction: "Mixed Addiction" tour - on 15% sale for the month of March
$64 gets you 10 reviews. That's $6.38 per review. (If you book in March)
My opinion: That seems like a fair price, and I heard decent things over at the Water Cooler. However, their website isn't exactly beautiful and I have a hard time giving money to someone who's too cheap to buy their own URL. Still, I'll consider it.
Promotional Book Tours: "Just Reviews" Tour
$125 for 10 reviews. That's $12.50 per review.
My opinion: They guarantee Goodreads and Amazon reviews as well, which is good. I haven't heard anything bad about them, but maybe I didn't look deep enough. It seems like a decent mid-range gamble. Professional website, etc.
Kismet Book Tours: currently closed to new books
$320 gets you 20 reviews (I've heard). That's $16 per review.
My opinion: Those numbers are hear-say. It got good recommendations from some author friends, and I guess they have a selection process of sorts. If your book is coming out in 2015, research them in advance. I'm sad I missed my chance.
Premier Virtual Author Book Tours: Basic 25 blog tour - 20% off for indie authors
$599 for 25 reviews, plus other appearances. That's 23.97 per review.
My opinion: It's not cheap- and if you aren't an indie author, the price is a lot higher. I inquired about pricing plans and got a strangely formatted, badly edited email. The site is sparse and rather suspicious as well. But like everyone else in the world, I'm a sucker for getting 20% off.
Book Nerd Tours: "The Super Nerd"
$225 gets you 6 or 7 reviews, plus some extra guest posts/interviews and whatnot. That's $37.50 per review, max.
My opinion: The reviewer in me is happy that they don't guarantee too many reviews- it makes me think people will actually, honestly, read and review the book with the intention of reaching their own set of fans. Book bloggers are swamped, and the legit ones don't read just any book- they read books they think they'll like. They don't say nice things about just any book either, and I want to hear an honest opinion. But the author in me says, "More reviews! That's not enough reviews for two hundred dollars!"
Novel Publicity: Personalized Tours
$1,000 gets you 20 blog spots. That's $50 per blog spot (not reviews!).
My opinion: That's a heck of a lot, and it doesn't even say if the 20 blog appearances are reviews or not. I'm not going to pay for it, but my publisher works with them (or maybe an affiliate of theirs) and I believe they are legit. Shell out the big bucks, and it might be worth it. They do guarantee a certain amount of traffic on the blogs, so that's a plus.
TLC Book Tours: The ten-blog tour
$549 gets you 10 reviews. That's $54 per review!!!
My opinion: Holy cow! That's expensive. Like a grocery shopper looking at over-priced organic food, my first impression is, "They must be legit." But even if they are, is it worth it? I'm not sure.
Oh God there's so many... Here are more, which I did not include because they either specialize in specific genres or don't mention actual reviews: