For beer, you will probably not to go below 1.000.
As far as benefitting from a lab grade piece, the question really is how. Will knowing your gravity to a greater precision help you to brew better beer? Maybe, but I can think of a number of different things that are generally more important for new brewers.
If you really want to get some nice glass, though, consider getting a few to cover the range. I'd have to check but I believe that my set goes from 1.000-1.030 (final grav), 1.030-1.060 (moderate beer OG), and 1.050-1.100 (big beer OG). I like 'em. I brewed for years before I got 'em, though, and was perfectly happy.
"Be excellent to each other." -Benjamin Franklin