I'll second that opinion, but add the caveat that you should evaluate your purchase of a fleet box on the basis of where the ships in it fall priority wise. To give you some more background by what I mean on this, there are currently 6 priority levels.
Patrol
Skirmish
Raid
Battle
War
Armegeddon
To try and give you an idea on what these mean, Patrol level are your light attack craft and fighter squadrons. Skirmish and raid are your destroyers and light cruisers. Battle and War are the heavy cruisers and battleships, and Armegeddon represents the really big and really powerful ships.
To give you an example, the Shadow fleet box is a particularly bad value at the moment because it comes with 4 Shadow ships which are all at armegeddon level. In the standard 5 point raid game you can't even field one of these so the liklihood that you'll be able to put all 4 on the table is effectively nill. Getting abreak on the price isn't that good if you can never use it in an actual game. I hear that is changing with the release of the second edition which will include a "Juvenile" Shadow ship that has a bit less power and drops down a level or two.
In the end, it is best to get the set with a number of counters so you can try the game with a few different factions to see which one you like best.