Much more efficient to steal something that is
(1) more expensive and
(2) easy to sell.
If they steal a bike that Derrek was trying to sell for $30.00, they don't have $30.00. They have a bike that *maybe* they can sell for $30.00. But they have to find a customer first, and meet with that customer etc. Severe pia if you're not into it. Where will they meet the customer? Where will they store the bike until they can sell it? How long will it take to sell it? Can they find someone who is interested in this bike? Seriously, not easy money, even if you steal the bike.
And it depends on what else is out there. If you have a bunch of inexpensive bikes and most people in your area have *nothing*, then you're probably at higher risk for theft, all other things equal. But if you have some neighbors with lots of little new tech-y things (expensive and very easy to steal, sell (maybe online), ship, etc.,) then the thief gets alot more for his time by passing you over.