Been hosed a few times with manufacturer recommended new vehicle servicing so checking in to get opinions and facts.

2007 Suzuki Eiger 400 (90 miles)
2007 Suzuki Vinson 500 (108 miles)

Suzuki recommends valve adjustment at the 100 mile servicing. My dealer just quoted $300 per bike (includes valve adjust, oil, inspection, yada yada). Frankly, I can do the oil change myself.

QUESTION: Okay, I know the valves are important. However, how likely is it that they will need adjustment and is there a way to audibly check if an adjustment is necessary? $300 per bike seems like a blow.