Eventually I settled on Back 2 Base-ix which is a awesome company I almost bought from before. The thing is, they are situated in australia, which makes shipping a bit expensive. Just bases is quite doable though.
I ordered some nice timber, dungeon stone and cobblestone bases. The timber ones are now being used for my mansions of madness investigators. The checkout process is quick enough and allows for paypal, not bad at all. The shipping was quite fast. I have had packages from the UK arrive later (and I live in Holland).
So what is the quality of these bases? Resin casts, not bad at all, though not top of the line. They don't need any sanding at the bottom, more filling up if you want them to look perfectly straight from the bottom up. The detail is not amazing, but quite sufficient for that classic dungeon/wood/cobblestone feel. I only spotted one cobblestone base with a minor defect. Pretty good! 7$ for 10 resin bases is also a pretty good deal.
Unpainted bases from all three lines
A quick white primer, that stuck very well, later and I painted up all the timber bases. I like my consistency and so I painted up all 20 timber bases, for future investigators!
Painted timber bases
Verdict: Good for what you'd get them for, good price. Would buy again. They are not the best bases out there, but the the value for the low price is quite nice.