Well... thanks to all your wonderful suggestions I went in pursuit of the best price to buy as much Dream dot as I oculd find... but then I came across Erin McMorris' Flower Shower in gold at the amazing price of 3.99 (it's a sale on Above All Fabric, go check it out). ialready had 3 fatquarters of the Wildwood collection - this exact one, the popsicle trees (unfortunately not the green version) and another one - and was planning on using them in my princess' baby quilt. These fabrics are actually the reason why I got so into the pink-green-yellow colourway in the first place. So it's only fair that I choose it for the backing. And with the money I saved, I can buy some Dream dot for the quilt top (and some other fabrics too, one can never have enough).
I'm happy happy happy about my very smart purchase. Now I just need to get better and leave this damn bed so I can start sewing. I'm 18 weeks pregnant and had my first contractions some days ago, the doctor said if I has any I had to stay in bed so that's not very good news for me and my sewing machine. But, as I said, I'm happy happy happy and I can be in denial until my next doctor's appointment :)