Found it
https://www.jehovahs-witness.com/topic/282651/boe-2014-07-15-witnessing-public-places-revision
BoE Letter July 15, 2014 - Witnessing in public places (note last sentence in para 6)
6. Requesting public witnessing equipment: The Congregation Service Committee will determine the equipment to be requested and where it will be stored. Public witnessing equipment can be requested in the same way publications are requested. We are pleased to provide a document entitled Public Witnessing Supplies (S-80) that contains sample pictures and descriptions of standard carts, stands, tables, and kiosks. The equipment will remain the property of the congregation. Care should be taken to request only equipment that will be put to good use by publishers who have been trained in its use. The congregation may be informed that the cost of these carts will be covered by their contributions to the worldwide work.
So, no direct cost, nor any suggested cost provided
That's all folks!
DarK SpilveR