Hi all! I arrived in Istanbul very recently and this is my firs post on this forum. The room I moved in has only a sofa bed that's not very comfortable and I'd like to buy a big mattress (just the mattress), at least 1.50 x 1.90 metres - or around that size. Does any of you happen to have something like that for sale? If not, any advice on where to get a good deal? I'm a little tight now and that's why I'm going only for the mattress and not for a complete bed. Many thanks in advance! P. S. I'm staying in Istanbul, right between Şişli and Beyoğlu, about 10 minutes walking from Taksim.