I note that the RRP difference is 'only' $2.76.
Hey - the ebook is available one day before the paperback, surely that's worth $2.76?
I suspect it's that the paperback is sold to the retailer at about 50% of the RRP and the retailer can choose what price to sell it at, but the eBook must be sold at the RRP.
But I've got no idea why the eBook RRP is higher than the paperback RRP. In the UK the ebook is £15.05 at Amazon and the paperback is £19.99.
Oddly, the ebook is only £7.49 at Kobo UK.