Skinning @ 300 is becoming more profitable now. To do a 'no kill' Dire Maul run you require a bunch of rugged leather, so people are paying a premium for it at AH. The prices will likely stabilize at a higher-than-usual price.
Dragonscales sell fairly well, often for more than the dragonscale equipment will. You can farm those solo at 60 fairly well.
With 300 skinning though, you can only skin mobs up to L60. There are mobs up to L63 that require Finkle's Skinner (+10 skinning) and the +5 skinning enchant on your gloves. The majority of people can't do this, but in UBRS you can skin the beast near the end for his hide, which is extremely important for a number of quests to obtain VERY powerful equipment (cap of the scarlet savant, leggings of arcana, breastplate of bloodthirst).
Yes, 300 skinning has its uses. At 225 you can skin mobs up to level 45, so until you reach a point where you need to skin higher level mobs, you don't really need to pay the 5g. In the long run, 5g is completely insignificant and should not deter you from your trade.
On Doomhammer, a stack of 10 rugged leather is selling for 2g buyout. 10 rugged leather takes very little time to acquire.