storage unit cost per month
1 A 5x5 foot storage unit usually runs about $40-$50 per month. 2  10x15 foot units cost $75-$140 per month or $115-$150 for a climate controlled space. 3  A 10x20 unit ranges from $95-$155 per month or $170-$180 for climate controlled. 4  20x20-foot spaces rent for about $225 per month.