Besides IKEA... Any recommendations on which chaines offer inexpensive but good quality mattresses?
Thanks in advance for any advice!

Hi there, we discovered Conforama had the best quality and discounts on their bed range. A premium mattress (200x240cm) was 1100.- (instead of 1800.-), delivery included. A friend also bought one there for a smaller frame for 700.- Here's the website: www.conforama.ch. The closest one to Zurich is in Schlieren.

Keep an eye out for Aldi and Lidl offers as they offer good mattresses guaranteed for 10 years for around CHF100.

What about 'Matratzen-Concord' chain? Do they have a good reputation in CH?

They are OK. Not cheap either though. Single bed mattrasses are 350-400 chf (w/out sale). We bought bed slates from them though. They started squeaking after 6 months... Got a 10 year guarantee on them, so I should actually call and ask to fix that (although I'm not sure it qualifies as something that can be fixed )

You might also want to consider LIPO. There is one in Morges..