The Barn is an excellent choice for a building, if you’re in need of Sumptuous Fur, Raw Beast Hides or various types of meat. But the true valuable material that a Barn can produce is Savage Blood. This crafting material is required typically for crafted item upgrades, up to 655, or further to 665.
Now, the average price for Savage Blood is 1600g at the moment, and it will probably slowly decrease for the next few months. But since it’s not that easy to get, its price should stay rather high.
So, what to do in order to obtain Savage Blood?
First of all, you need your Town Hall at level 2, in order to unlock the Garrison Blueprints: Barn, Level 1. Then, you need to raise your Barn to level 3, which requires you to complete the Master Trapper achievement. For this achievement, you must submit 125 Work Orders into your Barn. This can take some time, considering that the Barn processes only 6 orders per day. The good news is though, Master Trapper is an account wide achievement. Therefore, if you have several characters with a level 2 Garrison, you can get a Barn up on each one of them, submit orders with each character, and speed up the achievement.
Once you have your achievement and the Barn at level 3, you will be allowed to trap elite beasts, such as Wetland Tramplers, Ironhide Bulls and Direfang Alpha, and turn them in for Work Orders. Each order from an elite beast has a rough change of ~30% to drop Savage Blood as a by-product.
Evidently, you can have a level 3 Barn on several characters, and submit your daily orders, for more Savage Blood. And if you don’t need it for your own crafts, you can sell them in AH for 1500-1600g a piece (at least for now). Especially if you’re a PvP player, and get all the gear you need by playing arena and rated BGs, a couple of Barns on your account will bring you a steady, nice income.