Hi there,My sister and brother-in-law have one of your mattresses and they love it. We are in desperate need to replace the foam IKEA mattress we are on now. It's a EuroKing.I can see that you do offer this size as an Artisan model with extra cost. We'd prefer to avoid the extra cost, naturally. How much is it?I guess we could go smaller in width 150cm or larger 180cm. Because of our slats we will need to add some support under the mattress anyway. I wonder if we could get the 180cm and make the thin support extend out the extra 10cm on each side. Crazy?Thanks,Cameron