Those prices sound... inflated. In our area, service is something like $100/hour for all of that, plus the cost of parts. So I'd expect it to be:

• shower handle - $150-200
• AC clean service - $150 - in my area, there's a promo $75 AC clean service
• AC repair - $200-300 - extra cost for diagnosis and whatnot; probably done in 2 visits
• sprinkler system - $150 - though why would you pay for it? It takes like 30s to shut off the valve, and you don't need to blow air through it (I never do)

That said, I still do most of that myself. I hire out the dangerous work (gas lines, electrical breaker box, safety components on car, etc), but I'll do most of the rest myself, such as:

• oil changes - costs me like $35-40 each time ($25-30 for synthetic motor oil, $5 for OEM oil filters bought in bulk, $10 for air filter from auto parts store); that's about half the price of oil change places for synthetic
• fixed combination meter in car (Prius) - $100 eBay service and 2-3 hours of work (remove whole dashboard; would've cost $1k+ at the shop)
• replace sprinkler heads - $5-10 per head, and about 10 min of work (dig around it, unscrew head, screw new head on, re-pack)

And so on. It's usually faster for me to DIY since I don't need to call, change my schedule, etc, I just order the parts and do it when I have time, with a YouTube video showing me what to do. It probably takes me about 2-3x as long as a pro, but generally speaking, that time would be spent with me setting up the appointment, talking with the contractor, etc.