Eeyo posted:

I'm allergic to money so I got a serger recently, so here's what I've been reading. The used machines can be good, but people seem to think they can be a little more dicey than used sewing machines. There's more to go wrong, in particular the timing of the machine can be off. IDK what's involved with fixing that but it's at the very least more specialized than fixing a sewing machine.

My general reading is that the brother machines tend to be favorably reviewed. Over here in the states the common basic model is the 1034D, idk if you get that in Europe(?). I don't know much about the particular models.

Juki machines were also well-regarded and the feeling seemed to be that they were a bit more robust than the brothers. The common ones are the 644DE and 654DE (the latter one can do heavier stuff, is slightly easier to thread, and can take more needle types I think). They're more expensive than the brothers, but since they have a reputation for being more robust may be a good option for used.

Looking at the price of the 2104 and the features that's about what you'd expect for a base machine. For features you want at a minimum:

2/3/4 thread operation
Differential feed (this does great things for difficult fabrics)
Foot pressure adjustment
Retractable knife
Adjustable stitch length

The basic models are all compact like the 2104. They're like half the footprint of my sewing machine.

You should also avoid old models that you can't buy new knives for. You need to replace the knife occasionally and if you can't source it then it won't cut well.