Shower rings? iPhone cases? Banana Hooks? Watering Spouts? Whatever products you might create on your 3D printer as an alternative to purchasing said products, researchers at Michigan Technological University have determined that after a years’ time, you will most likely have paid for the 3D printer in money saved alone. Ultimately, this brings up perhaps a more interesting question: What do you actually use your 3D printer for that you would otherwise purchase?
When Does a 3D Printer Pay for Itself?
The study considered 20 of some of the most common household items listed on Thingiverse including smart device accessories, a garlic press, a showerhead, a spoonholder, and the like. Using Google Shopping, the researchers then determined the maximum and minimum cost of buying those 20 items online, shipping charges (and alternatively, gas/transport expenses) not included. 
Household items used in the study Once the team had a well-rounded list of the common household items and their average prices, they calculated the cost of making them with consumer-grade 3D printers. Their results? It would cost the typical American consumer from $312 to $1,944 to buy those 20 items online (again, not including shipping) compared to $18 to make them on their 3D printer over a weekend. Holy cow!
“With the exponential growth of free designs and expansion of 3D printing, we are creating enormous potential wealth for everyone… [Y]ou don’t need to be an engineer or a professional technician to set up a 3D printer. Some can be set up in under half an hour, and even the RepRap can be built in a weekend by a reasonably handy do-it-yourselfer.”-Joshua Pearce, Lead Researcher
Household items used in the study Once the team had a well-rounded list of the common household items and their average prices, they calculated the cost of making them with consumer-grade 3D printers. Their results? It would cost the typical American consumer from $312 to $1,944 to buy those 20 items online (again, not including shipping) compared to $18 to make them on their 3D printer over a weekend. Holy cow! “With the exponential growth of free designs and expansion of 3D printing, we are creating enormous potential wealth for everyone… [Y]ou don’t need to be an engineer or a professional technician to set up a 3D printer. Some can be set up in under half an hour, and even the RepRap can be built in a weekend by a reasonably handy do-it-yourselfer.”-Joshua Pearce, Lead Researcher
An additional bonus that wasn’t mentioned in the study is the ability to not only fabricate your own items at home, but personalize them as well: 
Also: these are just 20 of the most common household items. Yesterday, we posted on a man named Ivan Sentch in New Zealand who is creating a plug for a body mold for a 1961 Aston Martin with 2,500 3D prints on a $499 Solidoodle 3D printer—effectively saving him the $15,000 or so it would cost to have the same shape sculpted out of foam at a local CNC shop. 3D printer users are also printing replicas of rare vintage camera lens mounts, orthotics, vintage car parts, and other items that alone might cost 4x-10x the cost of a single MakerBot Replicator 2.
Also: these are just 20 of the most common household items. Yesterday, we posted on a man named Ivan Sentch in New Zealand who is creating a plug for a body mold for a 1961 Aston Martin with 2,500 3D prints on a $499 Solidoodle 3D printer—effectively saving him the $15,000 or so it would cost to have the same shape sculpted out of foam at a local CNC shop. 3D printer users are also printing replicas of rare vintage camera lens mounts, orthotics, vintage car parts, and other items that alone might cost 4x-10x the cost of a single MakerBot Replicator 2. 