I use the Mary Ellen's Best Press lavender for my qulting. I buy it at Mill End for $4.50 plus tax. Try some of the discount fabric stores. They are much more reasonable on things like this.
Remember that fabric has more threads running the legnth and so that is the most stable way to press/iron. But, if you do iron the width go with the grain. I hope this helps you keep the fabric from going wonky on you from now on.