Price sounds standard - you have a couple more cylinders to cover - I paid £25ish I think
The procedure on Audipages is sound - me and the wife did mine some time ago. Hardest bit I found was getting the gaskets to stay put to reinstall, and you may have to split a fuel line on the left-back (as you look under the bonnet) to get the cam cover off that side. Otherwise, easy peasy.