3d printing has come a long way! But while I faff over whether i need to buy a printer or not, I am at the mercy of market forces for pricing. The last quote i got for a high quality print of a 54mm figure was about AU$100 (this was in late 2018). But the kickstarters sometimes have affordable limited release 3d printed minis sub-$100. For example Heresy lab have had at least three successful kickstarters with an option to pledge for 54mm 3d printed miniatures. The quality of the minis is very good, though they are not as easy to work with as resin as the material is more brittle and hard to cut.

Agnes Sepherina, a 3d print from Heresy lab’s Sci-fi Heresy girl kickstarter
Elsina Hell, a 3d print from the heresy lab kickstarter
Deathshadow, a heresy lab 3d print.
Jade Devil, a 3d print from Heresy lab.
Ghost, a 3d print from Heresy labs.

A number of sculpts have also been made by fans or ‘backyard’ garages.

An amazing resin sculpt of an arcoflagellant from a member of the conclave forum (Thantos). More a side-service by a professional team than a fan sculpt.
The same arcoflagellant but with an arm swap
A resin fan sculpt of an imperial commander from a member of the conclave (Lord Borak)
Papah minis made this 54mm tau fire warrior as a garage kit many years ago. Called Alien Commander, it was a metal mini that had a variety of head and arm options. It also came with the severed torso of an imperial guard to decorate the base.
The mini was then released as a resin version and re-badged Alien Commander 2.0. There were 4 different arm sets, 4 bare head variants and 3 helmeted head variants.
Here is a metal version with one of the head options.
Another with a different head and arm set
another fire warrior with a different arm set
An inquisitor fan sculpt from a member of the conclave forum (Greenstuff_Gav). I think he made a few resin copies.
A garage kit 54mm mini in resin from Etsy. Now OOP.
A fan made cultist. Made by a member of the conclave forum (Lord Borak). There are three in the set (or is it four?)
Another fan made resin of an admech, inspired from a picture in the inquisitor rulebook. Made by a member of the conclave forum (Greenstuff_Gav)
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These are 54mm scale resin weapons made by a member of the conclave (Legio Destructor). Sometimes available on ebay. Some of the weapons are a tad big.
This alternate space marine head was commissioned by a fan. The head was sculpted by someone at GW (or ex-GW, not entirely sure which). I got this one from ebay.
Volomir (a professional painter) cast up this metal figure. Very hard to buy (they sometimes come up on ebay), but you get one (or used to) as part of his painting masterclass workshops.
I think this is a fan-made metal necron. It used to come up on ebay quite a bit but i haven’t seen it lately. I don’t know who sculpted it.

There are a few more fan made sculpts that were cast in resin, typically by members of the conclave. For example, someone made a Vostroyan guard head. Does anyone have it? Also i think there are a few variant eldar heads that have been cast up?