As this is all about exploration rather than a full commitment, I tend to used bureaux services where I need something created physically. While this is more expensive that it would be if I were to use my own tooling, it avoids the outlay needed to purchase the tooling in the first place. It also allows me to focus on the creation (play) and leave the technician skills to others. As always, your mileage (and interest) may vary.
Shapeways
I’ve used the Shapeways service (www.shapeways.com) to realise a number of my designs. They have a range of materials and are always clear on the costs before you order an item.