The Life-Binder's Handmaiden is an extremely low drop chance from the Madness of Deathwing encounter in the Dragon Soul raid on Heroic mode. It also has a chance to be listed on the Black Market Auction House.
Here you can buy Life-Binders Handmaiden for EU or US Servers.
You'll get guide for getting Life-Binders Handmaiden
You'll be able to get Life-Binders Handmaiden
Life-Binders Handmaiden mount
Additional budget for Character transfer or Character boost to max level. BMAH Services in Shadowlands now requirement to have a max level character on server, so Trial character will not work.
Free time on evening, if you choose selfplay option