The bicycle.
Let's consider one of the necessities in my life: transport.
If I took public transport, it would cost me about $50 a month.
My bicycle cost me about $200. Let's assume that the maintenance costs are negligible. Using public transport as a baseline for comparison, the yield will be 25% per month. Don't forget that cycling also keeps you healthy, which is priceless.
The only problem is that it doesn't scale, that is, you can't increase the returns as you put in more money.
Let's consider one of the necessities in my life: transport.
If I took public transport, it would cost me about $50 a month.
My bicycle cost me about $200. Let's assume that the maintenance costs are negligible. Using public transport as a baseline for comparison, the yield will be 25% per month. Don't forget that cycling also keeps you healthy, which is priceless.
The only problem is that it doesn't scale, that is, you can't increase the returns as you put in more money.