Uh ... it isn't typically a place to live. It's the 5' x 10' U-Stor-It where you keep the gear. It's the 'rent' for keeping the gear in the basement/garage of that contact's place.
Other than the first question, though, I'm not sure I understand your statement. Are you wondering why a) there's a 'lifestyle' selected at all, and why not just throw a R1 or R2 fake sin in there along with some cash to purchase a lifestyle? Well, this first assumes (as one always should) that your primary fake running SIN is blown. It secondly operates on the conclusion that a low-rating SIN is virtual suicide; a 4 is what is functionally necessary to move around in society without getting into shootouts with the cops once per linear mile. Third, it operates on the belief that if you have a bunch of stuff, you need to keep it somewhere; that's why the 'Squatter' lifestyle, even though it may not really be such (storeroom of the contact's bar, their basement, the compartment at the U-STOR-IT, whatever. Fourth and Last, that's why the L4 SIN is in there, which it doesn't quite seem you noticed.