Put Your Thinking Cap On

It's time for another round of guess the Mensa puzzle (provided by Rose's amazing Mensa Puzzle Calendar).

Charlie went out to buy some tools. He spent half of the original amount plus $10 for a drill, half of what was left plus $4 for a sander, then half of what was left plus $2, leaving him with $6.

How much did he start with?

I knew they were going to ask that question. I'll be lying down with a cool cloth on my head if anyone needs me...

HERE'S THE ANSWER
(in cleverly done "invisi-type" ... highlight it with your cursor to read ... rereading I discovered a typo so those who did the puzzle before I fixed it will have to add 16 to the final answer ... sorry!)

$100 ($50 + $10= $60, leaving $40; $20 = $4 = $24, leaving $16; $8 + $2 = $10, leaving $6)