There are extensive listings in the book "Spoor en Post". (No pricing though.)
They are also listed in "Benelux Revenues" by Barefoot. (Not as complete, but has values.)
Finally, there is also an online listing at: http://members.casema.nl/leobakx/
There are hundreds of types.
re: spoorwegzegels Dutch railway stamps
There are extensive listings in the book "Spoor en Post". (No pricing though.)
They are also listed in "Benelux Revenues" by Barefoot. (Not as complete, but has values.)
Finally, there is also an online listing at: http://members.casema.nl/leobakx/
There are hundreds of types.