Do you want to save £1500?
In that case you get yourself the smallest Ivar shelf from Ikea, which will cost virtually nothing. You add a couple of wheels to the ends of two of the four legs. You put some kind of handles on the opposite side of Ivar. You paint it a nice colour.
And that way you have yourself a nice, mobile bookshelf. Your to-be-read pile can always be with you.
Or you could buy one of these beauties; designer Matti Klenell’s The Truck. It’s just rather expensive.
The Occasional Bookwitch 
As someone who has moved a lot of books around with various carts , it’s whether they’re prone to tipping over that’s the question.
Best done before you open your wallet.
I suspect books might just fall off.