Engine didn't start 6 out of 10 times

2000 Passport EX- took to mechanic because didn't start 6 out of 10 times - 900$ later it doesnt start again. I believed the starter needed replacing but he said that it was just a spark plug that was firing out of its boot or something similar. I need to take it back but want to make sure I wasn't ripped off the first time. A)how do I insist they make it right without charging me again, and B) I want to make sure everything that is on my bill was really performed.

Here's a rundown of the receipt:air/fuel induction kit 44.99, 2 shocks 31.90, 1 steering gear 440.00, install gear 80.00, oil pan gasket 45.00, fuel induct labor 45.00, filter kit 80.00 free oil change. This was all done in 5 hrs.I know the shocks were changed because the old ones were blue they're red now. Does this all sound correct? Where is the the steering gear located so that I could look at it? How do I not come across like I think I'm being ripped off, but still get my car fixed like it should have been?

The steering gear located so that I could look at it? How do I not come across like I think I'm being ripped off, but still get my car fixed like it should have been?