my 1st 3D printer (Cheap). Help please.

[curious aardvark]

Okay for one thing you CANNOT GET A PRUSA for under 100 euros.

What you have there is a really cheap and nasty i3 CLONE that will require an awful lot of work (I know i have one). although probably less than the ender 3 - which is a piece of junk !

Secondly - updating firmware is generally a complete waste of time - also you will probably struggle to flash the cheap i3 clones. Although in their case you should. they come with a really horrible version of marlin. I'm not sure there i any other ;-)

But I currently have five 3d printers all different all with original firmware.
Never updated any, never needed to.
repetier and sailfish are both vastly superior to marlin in my opinion.

You buy genuine prusa's from josef prusa himself: https://www.prusa3d.com/

everything else is just a cheaper copy :-)

As far as bang for buck - given how much hassle you'll have with either a cheap i3 or an ender 3, you don't really get much bang - a lot of damp squibs maybe, but no actual bangs.

For a first printer I'd recommend a larger budget. Get something that might actually work, and once you've learned a lot more about 3d printing and can make your own parts. THEN buy a dirt cheap one as a hobby fix-up :-)

I'm quite happy with my ctc i3 prob (similiar to what you are calling a prusa) and it is genuinely a better machine than the ender 3. But it will takea fair bit of work to get it good. Less than you need for the e3, but mor than most printers need.