http://www.realityaircraft.com/
Looking at the website above, about £12.5k+VAT for a 503 kit, and about £16.5k+VAT for a Jabiru kit. Doesn't show a price for the trailer.
I'd say 70kn and 75 kn is about right for the two versions, but equally in my experience best range speed is nearer 60kn. It's not, let's be honest, an aeroplane for people in a hurry.
G