I replaced the magnetron in a home microwave. It was not dangerous or complicated. I was fortunate to have a good appliance repair store in my town and I don't remember the guy behind the counter thinking I was going to kill or maim myself. We looked up the part and it was substantially cheaper than a new oven. That might be different today but before I tossed the broken one, I'd investigate fixing it. It's not rocket science.
Your just lucky there can be a considerable amount of voltage stored in the high voltage capacitor. If it bleeds off not much of a issue but if it don't you can get zapped with thousands of volts. Your appliance store is a bunch of idiots for not explaining that to you.
Don't take this kind of information lightly people no its not rocket science but there is some danger lurking in there when you don't know what the heck your doing.