What's the value of a used book store?

I got to thinking about this the other day when a co-worker and I were talking about savings to be had at a Border's going out of business sale.  My co-worker had maid the comment that the prices were better than a used bookstore (at all books for $1 of course they were).  I think I must be looking at used books stores in the wrong way, because it's not potential savings that draw me to them.

I'm probably more cost conscious than most when it comes to buying books and if I'm patient I know I can usually find a new book at the same cost, or less than, a used one.  (By patient, I mean this process can sometimes take a few years from publication but it's not like I have nothing else to read.)  I have two categories of used book stores: the antiquities and the binge buying. 

There are certain places I'll go knowing that I'm only going to briefly scan the contents of the shelves looking for regular stuff to read.  I go to the antiquities stores when I feel like treating myself self to something nice--which I haven't done in a very long time.  If I want an Easton Press or Franklin Library book that is in 'as new' condition there are places I can go and lay hands on the books with a large selection to choose from.  Between deciding on what I want among a stores ever-changing inventory and browsing the rest of whatever other cool stuff is behind the glass case I can spend an hour in one of these stores.  I know that when I leave I'll only have spent thirty dollars.  Which is a value for the aforementioned books, but hardly a price one thinks of as a 'deal' when buying a single item at a used book store.

The binge buying book store is the place I tell myself I'll only go when my to-be-read pile becomes dangerously low.  That said, I end up at these types of stores far too frequently.  This is the kinda place where you have store credit, and the people know you by name, and expect you to help yourself to whatever you want, and they know you're not gonna be leaving for two-and-a-half hours... or perhaps I'm being too personal.  I go to these stores knowing I'm getting a heavy discount off the 'used' book price.  I know I'll thoroughly check eighty percent of the stores shelves.  Finally, I know I'll leave with fifteen to twenty books.  When I go on one of these shopping trips I'm never looking for the current best sellers--that's what I use libraries for (my recent purchase of Freedom was an exception).  I check for things on my 'wish-list.'  More often than not this list contains books that new books stores don't have on their shelves as the ninety day time limit has past.  The binge buying used books stores are a treasure for me: I don't know what I'll walk out with, but I'm always satisfied.  Sure I go for the savings, but as I don't know what I'm hoping to leave with when I walk in it's hard to say I go to binge buying book stores solely for monetary reasons.   

My co-worker likes to use used book stores for savings on the latest best sellers, which makes perfect sense to me.  But I know that even used book stores like to maintain some semblance of profit margin on inventory that they feel is certain to be in demand: e.g. used copies of current best sellers.  

I feel like my co-worker is operating as most people do with used book stores and I'm the weirdo.  That alone is par for the course in my life.  How does everyone else use their used book stores?  I'm curious if there are other awesome aspects of used book stores that I'm not fully appreciating.