Blake comes from a town in the NCR called Oak Creek. Oak Creek was once a farming town, but it was taken over by ranchers during his stay. Blake says that he didn't want to herd brahmin for the rest of his life, so he signed up with the Crimson Caravan.
He appears to carry 40 caps worth of cards every rotation.
Every once in a while, Blake will spawn with a high amount of caps. Usually exceeding 12000 and having a few rarer weapons such as the ballistic fist and thermic lance. It is unknown if this is a bug or a random chance. (May happen when returning from Dead Money or resetting the cache.)
pcps3xbox360 Blake normally stands in front of his "store," however he has been known to disappear (or not appear at all). If a careful search of all 3 outbuildings produces no Blake, try visiting the Caravaneer's building (first on the right as the player enters the Crimson Caravan map from fast travel). There may be a crowd of Caravaners standing close together (stuck). The player's entrance should cause them to start moving on their pre-programmed paths again. After the crowd disperses, Blake should be back in his normal position (and the town should appear much more lively). [verified]
xbox360pc It is possible for certain sections of his inventory to apparently not restock throughout the entire game, such as the aid section. On the PC, you can use console commands to make him restock. Bring up the console, then click on Blake to select him. Type "kill" and he will drop dead when you close the console. Bring up the console again, click on him again, and type "resurrect". When you close the console he will come back to life and have a restocked inventory. [Worked for me - needs more testing to confirm and to find out if this is only a temporary fix or whether his inventory will correctly update from then on] [verified]
In addition, Blake's caps may never replenish as with his entire inventory. [verified]
xbox360pc When dismembering Blake's head, two may appear. [verified]
xbox360ps3 There is a bug whereby items purchased from Blake in poor condition will be fully repaired in the players inventory. There is also a bug whereby if two of the same item are in Blake's inventory in different condition, and the player purchases the poor condition item, it will be the good condition item in the players inventory. The amount of caps removed will be that of the poor condition item. The latter glitch can be used to make unlimited caps.[verified]
xbox360pcps3 There is a bug when buying playing cards From Blake, the game will crash.[verified]