Been there, done that. You see, I buy a lot of used books from places that don't even have a catalogue. I can see why people wouldn't want to do that, though I personally find it kinda fun.

Switch to the online world though, and the desire to avoid shopping around is pure laziness. For one thing, it takes 1 minutes to get to another store (not 15 minutes) and it takes 10 minutes to browse the section that interests you (not 1 hour). Shopping from multiple vendors also keeps the ones that you prefer honest since maximizing revenues and minimizing expenses only works if your customers don't walk away.

Oh, and if multiple vendors are really too much trouble for book buyers, there are aggregators.