Iv sedation for my autistic daughter?

Just got back from the dentist she has one obvious cavity.. the dentist "sugested" she has about 8MORE. That might be coming through which I think is a crock of.... mind you she thinks this without even getting sufficient xrays. Anyways she said my daughter needs IV sedation which I am not ok with!! I'm terrified to put my 6year old fully asleep. Is there any other way how would general anesthesia or laughing gas make her? Wouldn't that put her semi to sleep? I feel like dentist jump to IV sedation because its just easier. Mind u it will cost me 700$ and that's with dental insurance.. any advise or opinions?