Yeah, I seen a guy buy oil and PUT IT IN HIS TRUNK. Did not help the car any. So, you need to learn some mechanic basics on how your car works because most of this is eyeball inspections you can do.
Shop around . There are shops that do it for cheaper. They have the tools and KNOW WHAT THEY ARE DOING. They will take the oil out of the trunk and drain the oil in the motor and give it new stuff. Kind of like changing a diaper.
. You don't say the car make. A RollsRoyce or Lambo costs way more than a Fiat 500 because you can AFFORD IT...so everybody is going to take advantage of you.
. Or go to a big box store auto service and let them do it because even they know more than you. Does not cost $150 unless you take 10 gallons of oil and have 5 filters. Most cars have 1 filter and 4 quarts of oil. Filter cost the cost of 1 quart of oil. So for under $40. you should be done.
Millions of sheeple go there and get it done. Millions can't be wrong.
I forgot, Kiwi-land must have their own big box store brands that do oil changes. So pick one and have it done. Watch while they do it. It is pretty basic. They may find other problems because you should see a mechanic once in awhile because cars break down or parts wear out such as brakes, exhaust, fan belts, batteries, tires, and even more.