I used to be into model railroading - sink hole for $$. No ROI there. I agree pinball is better than most hobbies as the resale value holds and the machines don't have many consumables other than new rubbers, lights, a broken plastic or occasional fried board. No registrations, license or insurance to buy. No need to travel to enjoy.

But my photography has a much better return as I sell my photographs.

Great Lego models! That battleship collection is amazing. Although I wouldn't put Legos in the cheap category. I'll reserve that for one of the best low budget hobbies - hiking.

All you need is access to trail head, a pair of hiking boots and off you go - excercise, fresh air and a good view.

I'll put x-country skiing in a close second place. Skis last many seasons, no lift tickets. Trail passes are inexpensive.