Dentals can get very pricey when there are extractions. If you look at your receipt, I am sure that is part of the reason it was so high.
I would not want my pups sitting all day like that either. If you like the vet, maybe next time you should just tell them that you want the procedure done earlier...or ask if you can bring them in later. Some practices do dentals late in the day... my vet has never done it. Could be a scheduling thing. I don't know.
Don't beat yourself....once you knew it was needed, you did it! Makes you a good mom!
And, I know, I hate to see mine lose teeth, but sometimes it happens and 3 is really not a lot. One of my pups lost one last year and she had a dental 11 months before that...just happens with some of them.
Glad that they are home with you and ok!