I think people have a number of concerns about buying online:

First, new cyclists should not buy a bike and assemble it themselves unless they are willing to take the risks and are careful enough to doublecheck everything (cables, housings, chain length, tightness of screws). Most new cyclists arn't this experienced, because its not just checking once the bike is assembled, its retightening cables after 50-100 miles of riding as many parts break in and stretch slightly.

Second, bikes are somewhat like clothes -- they come in sizes and some parts (like cleats) needed fitted correctly so you don't get problems with knees later on. Buying a bike from mail-order (or a low department store bike) may force you to throw more money at it later on than buying a decent bike initially.

Third, bikes are delicate. If packed improperly, you might have components like wheels going out of true, bent derailleurs and forks, and other mishaps which will bite you after you accepted delivery.

If the LBS in your area isn't good, have you considered driving to another town, checking there? Usually there is some LBS in a geographical region who will take good care of you.