Business Central OnPremise Viewer licences (Type Team Member) Problem high costs

Gollum83

Hello together,
perhaps could you please help me with the following problem:
A potentiell customer will need, besides about 10 "Full User",
about 300 Viewer licences (Limited, Read Only) for Business Central OnPremise.
The most of the Viewer Users look perhaps once or twice per month
for a short time into the application.
Anyway through the Named User licence modell they would have to buy
300 Viewer licences (Type Team Member) and also pay yearly support fee,
which would lead to very high costs.
Is there a special arrangement possible for Viewer licences,
that they can be in "concurrent" licence mode?
Or is it possible to buy even more limited Viewer licences
which have for example only a short amount of objects accessable
(e.g. 20 tables and 30 pages) and so reduce the costs?

Thanks
Kind regards