There were 9-4 = <<9-4=5>>5 other pills
Each of the other pills cost 1.50+5.50 = <<1.50+5.50=7>>7 dollars each.
The 5 pills cost a total of 7*5 = <<7*5=35>>35 dollars.
The first 4 pills cost 1.50*4 = <<1.50*4=6>>6 dollars in total.
Henry spent a total of 35+6 = <<35+6=41>>41 dollars.
#### 41