Volkswagen: vacuum leaks in my golf, vacuum pipes, vacuum leaks

Question
i have a 98 vw golf with just under 120,000 miles on it.  the car was running rough so i took it to a tuffy shop where they told me i had a vacuum leak and that they would also run some engine cleaning thing and that all that would be $150.  i dont know anything about cars and was just happy that it was going to cost less than $200.  however after it was done and i looked at the itemized receipt, the "fuel cleaner kit" was $40 which included air intake cleaner, valve injector cleanerand  power fuel treatment.  the labor was $60.  so that accounted for 2/3 of the bill.  i was just wondering if a vacuum leak would be cause in and of itself to do the engine cleaning or maybe the high mileage?  im feeling like a may have been suckered.

Answer
without seeing the car before hand, i cannot be certain as to what effect the cleaning has had. however, i have never had to clean the entire intake system and fuel system. on vw golf's, there is a common running problem caused by the throttle valve becoming clogged with carbonised oil. if this is one of the components that has been cleaned then it would justify the cost. also the vacuum pipes, especially the plastic brake servo pipe are prone to cracking in older cars and cars with high mileage due to the heat in the engine bay. it may seem expensive, yet it may actually have been required to carry out the above work. hope this helps to settle your mind one way or another.