Donation for a book review?

With my second book just released, I am once again trawling the internet looking for possible book reviewers. I'm happy to say, that the response has been great so far, but...

One of the book review sites answered my query saying they would love to review my book. Before they would review, a donation was required to help offset their website costs.

I was little taken aback by this and a bit uncomfortable. To me, it felt too much like buying a review. I responded and respectfully withdrew my review request.

There are a couple of things I'm thinking about this:

Surely the website costs are the responsibility of the reviewer. And while I understand it can become costly, they can always recoup through affiliate programs if their website is generating enough traffic. Secondly, it's their hobby, why should I pay for it?

Am I being too harsh? Has anyone else come across this type of thing? Is this the way of the future for indies to get reviewed?

Thanks for the feedback folks, I felt certain my instincts were right.

I keep a record of all potential reviewers, this one has been deleted never to be revisited.