@Blue Orange I would think that when you order you agree that if you don't return you buy them. That's easy to admin and there is a lot of precedent for it. Don't make it punitive. Make it an upsell. If you love the minis, great, just keep them and we'll charge the difference. I believe that is what NetFlix used to do, before streaming, when they were actually shipping movie/game disks to rent.
For me they would compete with the print-your-own-minis people, because I looked into 3D printing and drew a line in the sand. I don't need yet another sub-hobby to my hobby. Maybe 3D printers will get to the point where they are inexpensive and convenient enough. But even if they were, I don't necessarily want a huge amount of clutter and I don't have time to paint etc.
Obviously if the minis and terrain are painted that would make them that much more attractive, but also that much more difficult to make profitable (the time to paint them, touch ups when they are returned with nicks and scratches).
I think the idea is interesting, but I'm not sure if the potential customer pool is big enough. If it is, then this is a scalable model, but it seems that you will need a lot of subscribers and renters to turn a profit. I would do a lot more market research before throwing too much money into it.
There are some business I'm aware off, including on in my area that provides TTRPG parties and private conventions. They'll arrange the space, the adventures, all terrain, catering, and DMs to run the games. It can be a 6-hour birthday game or a multiple-day private convention for you and your friends. I could see groups like this also rent terrain, space, etc. E.g., if you are a DM and would like to run a special game, you can order everything but the DM.
Have you tried to network with professional DMs in your areas or game stores? Before moving to large-scale shipping, can you find ways to partner with professional GMs who want to up the wow factor of the pay-to-play games they run? Same thing with streamers? I'm guessing most streamers get terrain for free as advertising. Not sure whether any would pay for it. As for game stores, ask if you can put up adds in the store to for providing terrain and minis for games. E.g., create some really cool terrain and mini sets, all painted, for some of the most popular adventure modules. Then offer to print it all and set it up at the game store for the DM. Again, not sure how many would pay for that and how much you'd have to share with the game store. But it is worth exploring.
It would be cool for example to have sets prepared for all the Candlekeep adventures.
For example, with my current campain, I've the party survives to the end battle, I'm seriously considering hiring someone to co-DM it for me, especially if they can bring top-end terrain and painted minis.
Anyway, good luck! Report back on how it goes.
