Salve Dancinglonely,
as far as I'm aware neither...
- costs regarding/concerning transport and insurance should be charged to us
- please arrange to have costs regarding/concerning transport and insurance charged to us.
Hope I've understood...
so it's for what concerns transport and insurance costs ... and not THE transport and insurance costs,right? but I think we can say also concerning the transport and insurance costs... right?!
I would say it is rather weird, NicoleSery. If it were not, there would be at least a few hundred hits on Google Books for the phrase. As it is, there are four, two of which aren't relevant.
It is not correct to say *For what concerns X. You can say: Concerning X, As far as X is concerned, Regarding X,
With regard to X,
With reference to X,
As for X,
As to X,
or (more colloquially) As far as X goes.
Applying those to Dancinglonely's example, I would say As far as transport and insurance costs are concerned, please charge them to us.