Congrats OP, this is certainly a good success story. However, people need to keep in mind the OP used 3 bots over the course of 5 months to acquire the gold. Here are some figures to give you a better idea of the effort it takes.
450,000 gold
150 days
3 bots
---------------
= 1,000 gold per day, per bot
$1,125
150 days
1,200 hours
(assuming 8 hours per day)
----------------
= $0.9375 per hour
Also consider aprox $250 as a start up cost for the accounts and HB license. 3 accounts x 5 months is another $225 in subscription fees, then add in power to run your computer and any maintenance costs.
In short, unless you have an army of bots you are not going to get rich from selling WoW gold. It's a hobby for the majority of people. Unless you're willing to spend a considerable amount of time and money then you will not make a stable income.
It's fine to sell some gold on the side for an extra few bucks. But as someone else stated - get a job. You're pretty likely to find something that pays better than 93 cents per hour.