This really IS weird, because I was doing some comparison shopping over the weekend, too, and I get entirely different prices from what you're reporting.
At Kobo, I'm showing $11.79 for the Anne-Maire MacDonald book. Amazon.com shows $6.89 for the Kindle version of the first book.
It's strange, too, because I checked out the three books I had posted to my wish list in the Sony store - priced at $12.99, $12.60 and $12.55 at Sony, up from the prices listed before April 1st. At Kobo, the same books were uniformly $9.29 each. (A 4th book priced at $12.99 at Sony isn't listed at Kobo.)
I was wondering if Kobo simply hasn't yet raised their prices, due to the Easter holiday.
Curiouser and curiouser....
Cheers,
Bev