An apple vendor sells half the number of existing apples plus $1$ to the first customer, sells $1/3$$^{rd}$of the remaining apples plus $1$ to the second customer and $1/5$$^{th}$ of the remaining apples plus $1$ to the third customer. He then finds that he has $7$ apples left. If each apple costs $Rs.12$, then the amount of money he collected while selling apples is _______