If you're leveling a Warrior or Paladin, whether you're dps or tanking, Berserker Bracers will be an investment worth your time.  These bracers will be used from level 40 when you first learn proficiency to wear plate, well into Outlands.  The cost is 422 Honor and 20 WSG marks.  One thing to keep in mind is that the level 30-39 bracket is the most played and twinked bracket after the 19 bracket.  By the time you have 20 WSG marks, you will have more than enough honor to buy these bracers.

　Is it really worth the time and effort to get these bracers?  Well, lets see what the next upgrade options are. (Assuming you're not going to run Dire Maul, Strat, UBRS, BWL, AQ)

[See options]

As you can see, there is a lack of options for plate bracers while leveling.  So the best option would be to do WSG at level 38 or 39 to get 20marks for these bracers.  Even if you're totally unlucky the maximum amount of WSG games you would have to play would be 20.  You could spread the games out over 2-3 levels, or find a good time where your faction is having a winning streak. 

Enchants will also give these bracers an extra boost while they last you a good 25-28 levels. 

Enchant Bracer - Brawn (12 str) is a good option.  The mats are 6 Arcane Dust. Most greens from Outlands will disenchant into Arcane Dust.  They should be relatively cheap on the AH. 

Enchant Bracer - Fortitude (12 stam) is a bit more pricy but better for those who prefer stamina. The mats are 20 Arcane Dust, 10 Greater Planar Essence, and 1 Large Prismatic Shard.

Enchant Bracer - Major Defense (12 def) is for tanks.  The mats are 10 Arcane Dust and 2 Small Prismatic Shards