If you can't afford expensive storage here is a idea that you can use till you are able to buy the good stuff.
Ether go to a house demolition site or a builder's yard and collect (this is for small size shelving ),stack no more than two bricks on top of one another do the same with another two ,spacing them as far a part as you like add a length of timber or shelving across the two layers of bricks and then another two layers of bricks on top of the wooden board. (you can safely add three levels of shelving this way .For added stability try and get bricks that have holes in them and insert either a length of dowel or very thin metal piping. This method is recommended especially if you have small children.