Thank you for this info, Robin, I will certainly ask them for a quote :-)
Well..
If we are talking low cost, then even better option may be Edmund Scientific, here:
http://www.edmundoptics.com/onlineca...productID=1490
For the same price you can get a pack of 15 gratings.. 12700 l/mm (possibly too much for general spectra, but great for line profile details.. )