We’ve complained about the price of 3D printing filament, and cheered at the machine that makes filament out of plastic pellets. Still, the price of filament for our 3D printers is climbing ever higher, leaving us to wonder, where can I get the cheapest filament?

Now, I’m going to start this of by saying this is a work in progress. Canvassing suppliers on every continent for 1.75 and 3mm ABS and PLA for every possible color while accounting for different amounts of filament and shipping is a whole lot of work. Therefore, we’re going to do this in parts, first starting with how much it will cost me to get a kilogram of PLA shipped to my door. This should be a valid test for just about everyone in the USA.

The test criteria is simple: find a supplier of PLA on the Reprap wiki printing material suppliers page and figure out how much it would cost me to get 1 kg of white or natural PLA shipped to my front door. I’ve organized this in a spreadsheet (below) that contains the supplier, size (1.75 mm or 3mm), weight (usually 1 kg although some suppliers are about three ounces short), color, and price with shipping included.

As you can see, the cheapest place to get PLA filament is from eBay user kbellenterprises at $27 per kg. The mean price on this chart is $43.93, SD = $7.74.

Knowing that, the cheapest places to get filament – less than 1 standard deviation from the mean – are kbellenterprises, Matter Hackers, Just PLA, Maker Geeks, Monoprice, and 3D printing supplies. Amazingly, kbellenterprises is two standard deviations below the mean price. Either this guy is selling junk – not likely given his eBay feedback rating – or running a business on eBay is a whole lot more efficient than starting a webstore from scratch.

The most expensive filament suppliers – more than 1 SD away from the mean – are Ultimachine, Makerbot, and MakerGear. For those of you complaining I didn’t test for normality, go ahead and run a chi-squared. I’ll put it up.

Like I said, this is a work in progress. If you find any errors or omissions, send them in on the tips line and I’ll correct it in the Google spreadsheet.