For Odie and anyone else who can --- Amazon Japan is currently listing MP Prowl and Bluestreak for pre-order with the earlybird discount of 5098JPY (16% (992JPY) off RRP) -- about AU$53. It's marginally more expensive than Lambor's preorder price (4436JPY/$46) and Amazon doesn't seem to be offering any bonus exclusive accessories, so comparatively it seems to be poorer value for money.
But I don't think I can find them cheaper.
I don't mind paying a bit more if these toys turn out to be better than Lambor though. (here's hoping)