Hi Elisabeth,
Actually we had the same issue but internally. As I introduced the methodology to our company Haufe we started out with a standard set. With more and more facilitators joining our internal LSP community we did the following set up of bricks as they need them for the workshops:
10 Starter Kits mixed together to form the basis for a LSP workshop
1 Landscape & Identity Kit in combination with the Starter Kit buffet
20 Window Exploration Kits in Zipper Bags for Skill Building
We do not use the Starter Kits for Skill Building any more – only Window Exploration Kits – as the simpler logistics outweigh the benefits.
In order to store this setup we use the blue boxes from Lego Education as they sorting trays of the Identity and Connections Kits alike fit in perfectly.
This setup is easy to transport by car.
By plane it gets a bit trickier.
So we use this Split Roller Bag from Dakine. Everything from above except the blue boxes fit in there perfectly. To secure the trays we use wrapping foil around it.
This is the basic setup and it fits nicely in order to use with more than 5 facilitators.
If demand in facilitation arises you can always start to add an Landscape & Identity Kit and Starter Kits as well.
The Connectors Kit is used quite seldomly so you need to decide if you want to have one.
Additionally we keep our storage always with a bunch of extra Window Exploration Kits if we need to do a group session 20-200.
With this setup it should be easy to split the costs amongst your group of facilitators or – as I have seen that as well – One is buying all of them and charges a usage fee by the others to cover the costs over time and to replace the bricks from time to time.
I hope that helps.
Best Manuel