not sure how profitable this will still be but here it goes
(havent seen this posted before sorry if its repeted)
Requirements:
a lock with epic lock mount items
locks desperate for the mount
How:
simply search for lvl 56-60 locks and PM them asking if they will require help obtaining their epic lock mount.
all they need to do is the quests leading up to the quest in which u need to buy the items required to summon the mount
offer that they can use yours for a "small" fee.
get them to get a group together. and well..... do the DM run.
if it doesnt look like they are gonna pay u can always bail and leave them there!!
(i always use to roll with the whole "nice guy" act of payment isnt required but most/some give between 40 - 100g. for your troubles ofc) made well over 1.5k with this.
............
be warned i have not tryed this since TBC.