Let's do the calculations:

Ground mount ------------------- 45g
Epic ground mount -------------- 700g
Flying mount -------------------- 900g
Epic flying mount --------------- 5200g
Cold weather flying ------------- 1000g
Dual specialization ------------- 1000g

Total: 8845g (without reputation discount)


Recalculations at Honored reputation :
Ground mount -------------------   40.5g
Epic ground mount --------------   630g
Flying mount --------------------  900g (no discount)
Epic flying mount --------------- 5,200g (no discount)
Cold weather flying ------------- 1000g (no discount)
Dual specialization ------------- 1000g (no discount)


So you save something around 75g from being honored, yay..

For 10 characters, one of each class, you would have to do more detailed calculations as paladins and warlocks have cheaper mount training.  Druids also get cheaper slow speed flying form.  As for me, I'm looking at total of 70,251g for my characters.  God forbid I level all of my characters.  I don't think I could ever make all that money.  I would have to make 100g everyday for 2years to make that much money!  /faint

Edit Expense log-
Bought Dual spec on my paladin. 69, 251g