Consider what your van insurance covers, for example what can you carry in your van? What value of goods will be insured? Remember your tools car cost lot to replace.
Never go with the first van insurance quote you receive even if it looks reasonable, always compare quotes to see that you get everything you need included in the price.
You can reduce payments by offering a voluntary excess, but keep in mind not to offer a huge sum as you will need to meet it if you make a claim.