My 6yo had 3D printer in school and now is super excited about 3D printing. I'd like to get one of these but have no clue what are the criteria when purchasing one. Can someone help in assistance what to pay attention to while choosing such device? Obviously one of the main criteria user friendliness so that 6yo could quickly start using himself.

Bambu Labs. They have three interesting models:

* P1S: enclosed printer which can print most types of plastic and is extremely fast. It's a CoreXY printer meaning that the print head moves in XY position and the print bed only in Z. This makes it faster and take up less space. Controls via buttons and old style LCD display (3rd party touch panels are available). Available for 560 EUR base, 772 EUR with the AMS.

* A1: open printer which moves the bed the Y position, known as a "bed slinger". It's slightly slower than the P1S due to the bed moving but is still very fast. Controls are an integrated touch panel. This is their most modern design so it's easier to maintain. Priced at 300 EUR base, 450 EUR with AMS Lite

* A1 mini: small version of the A1. Main attraction is the price of 200 EUR base, 350 EUR with AMS Lite (+20 EUR postage).

Now the AMS (for the P1S) and AMS Lite (for the A1/A1M). These are their multiple material system. They allow you to use multiple different materials (colors, different plastics) at the same time. The AMS is enclosed and can be used with materials which must be kept dry (25% humidity in my AMS vs 80% out in the open). I have both and they're both awesome but not 100% required.

Prices in the US are lower as EU prices include 21% sales tax.

What to do? Buy the A1 mini if you're budget constrained or aren't sure. It's fantastic, it prints fast and the 18cm x 18cm size is fine for what kids will do with it. If you can stretch to the P1S then I'd highly recommend it. I brought all 3 for my business and have been running them together pretty much all the time I've been able to have them running. I use the mini for fast prototying and the other to make "production runs". Although I'll probably end up either moving the mini to private or buying another mini - as soon as the kids get started we won't be able to stop.

If you're in SV and have an SV budget for toys then Prusa are releasing a new CoreXY printer early next year. Their printers are more sustainable then Bambu Labs, they're not Chinese and are the market leader in quality. They're more capable than any of these printers too as they can print pretty much anything out of the box. I'm not sure if they have a multi-material system.