Hi Derek,
Go onto the Noble Express website and search for wet and dry vacuum.
They have a wet vac called an aquavalet HD55 which i have several of and use on a daily basis.
At the moment, they are £ 206 each with free delivery.
When i bought mine they were £99 delivered on a special offer, but they are still much cheaper than
what you have been looking at and the same thing with a plastic tank.
You need to watch for special offers, as offers are always changing on there.
Tim.