"The number far outstrips the company's 3,000 monthly sales target for the new model, which is called the Prius Alpha." Little more here: Toyota: Prius minivan orders well above target - MarketWatch
The market was very different back then. Think about how the technology has advanced, especially with respect to production cost and proof of reliability. For that matter, gas was still cheap back then too. .
even if we assume that it will be 5k/month, thats fairly huge number that makes it top 10 vehicle and also most expensive by far among those top 10.
I think being able to get a Prius Alpha 7-seater and pay an extra $1800 for shipping is reasonable. The only problem is the driver sits on the right (RHD) and I'm not a mail carrier. Food for thought... I just Google'd Batfa+prius+2012.
That rear row is worse looking for leg room than my RAV4, which is already beyond awful. Toyota must think there must be a lot of families with amputee members.