I looked at one similar to this, but it was from Babies R Us and was £50. The only reason I wanted it is because the house we are living in only has a shower, no bath, so I wanted the bath-on-wheels. But as we should now be moving before LO is born, I've not bothered.
I personally haven't got a changing unit. I think they are a waste of money. Most of the time, you will get down on the floor and change them there, and once they get big enough to roll, you can't use a changing unit anyway.
Saying that though, that is a lovely unit, and if you want it, go for it!