Dealer quoted me a fortune for major service, is that normal or am I being ripped off?

[honoriagrimble]

My 2017 430i is about to hit 100k km and I know it's due for a major service, probably spark plugs, all the filters, brake fluid, maybe transmission fluid too. I called the dealer just to get a ballpark and they quoted me something close to 4500 dirhams which honestly felt like a punch in the gut. I'm not trying to cheap out on maintenance because I know these cars need proper care, but that number seemed way higher than I expected. A friend at work told me to stop wasting time with the dealer and look for independent specialists instead, said he found a site that does Affordable major service for BMW cars and saved a ton. I haven't booked anything yet because I'm still nervous about whether outside shops use genuine parts and actually follow the full checklist. Has anyone here done a major service outside the dealer? Did you notice any difference in how the car runs afterwards or did something go wrong later? I want to save money but not at the risk of damaging the engine. Any real experiences would really help me decide because I'm stuck between paying too much and taking a chance on a random garage.