So today I noticed that my old Cafe Corner set which has been on shelf that gets lots of sunlight from my rather large window, and has been there for couple of years now, and I've noticed how clearly it's white parts (and even some minifigure torsos) have started to yellow, at least the parts that have been in direct contact with sunlight, especially HOTEL sign looking rather ugly from the other side. I'm sure there are lots of places on the internet that tell how to restore yellowed plastic, but I'd like to get opinions from Lego community itself on the subject that is it worth it trying to restore yellowed Lego parts somehow, or would it be better just to try to buy replacement parts?
Also in general, how risky is it for Lego parts to yellow simply buy keeping them on display on the place where they get lot of sunlight? My room is rather small with big window, and especially on summer, for most of the day sunlight comes almost directly into right side of my room where I keep some of my Legos with big white parts.