Is a bill of $1700 excessive for a deep cleaning?

I went to the dentist Monday and they did a 'probe' of my gums and found that I had some 4mm pockets in my gumline and they showed me a bill of over $700 to 'clean' my teeth and gums. This was not the total bill, they charged my insurance about $1700! I flipped out! They then discounted it $200 for me so I paid over $500 to get my teeth cleaned. I still don't believe it could possibly cost that much! I still feel shafted. I mean they cleaned my teeth! Seriously! They dug deeper, maybe put some antibiotic in the gums, gave me numbing agent... but is that $1700 worth of work???? It is not like I had a gold filling!!! I think it is a total scam. I am sure I needed the cleaning but the cost is completely outrageous to me? Is this normal??? If anyone out there who is a dentist could comment I would really like to know what it is that could possibly cost that much to clean teeth!