It could be worse.. blacksmithing is far worse to level than leatherworking. Mainly because we've got smiths, engineers, and jewelcrafters all needing the mining ores, while skinners only have leatherworking to support for the most part. Unlike ores, there's a virtually unlimited supply of skinning mats available if you farm the right areas. Need rugged leather? No problem... Un'goro. Need knothide leather? No problem.. Nagrand. (And get a lot of clefthoof leather while you're at it.) Leatherworking does tend to need a lot of mats per item (like 15 knothide leather), but I can't tell how much Thorium it's going to take to get me to 300 smithing at 12-16 a skillup. Leather is usually cheaper on the AH, so although it may be expensive, it's better than an alternative profession...
Get a head start on those rare mats drops like the nether scales.. by the time you've got enough of those, you should easily have farmed enough knothide leather to get you close to 375.