@Mike Magliette, Yes, I too like the idea of Converting old warehouse space. I am actually on the tail end of a project where we converted a 45,000 square foot facility into 33,300 rentable square foot of storage. We've got everything from 5 x 5 units up to 24' x 48' units. It's viable model for sure. Generally faster than ground up development and can usually happen at a lower price point (ours will be $27 per square foot inclusive of land).
And maybe I am nitpicking here put I would respectfully challenge the idea that "in order to grow you have to use leverage" and instead suggest that while leverage can be a very powerful to to increase the rate of growth, it is not a necessity. We are growing without using much of it at all. Though we did use it to accelerate growth when we first got started. It should also be noted that leverage also has the ability to erase a lot of growth pretty quickly. Like all tools, it can be very powerful if used correctly and it can be dangerous if not used properly. I'd suggest that far too many (and given that I don't know you, we can agree that this isn't directed at you in any way:) use debt irresponsibly and end up building a house of cards.
Regarding your comment about no appreciation in Scranton, I'm guessing you mean that there is no "organic" appreciation! In the storage world (perhaps more so than any other asset class), the value of the property if based on the value. As such, your increasing cash flow will force appreciation. I recently took a $465K property in the poorest and least populated county in all of Florida to a $1.2-$1.3 Million valuation...belief me when I tell you ALL of that was forced...Like Scranton, we don't have the benefit of organic appreciation.
Just some things to think about as you get started in storage!