I just looked on Amazon for price comparisons for pumps they are any where from $50 to $300. I'm not sure where the one service tech got $500 unless he's trying to increase his take home pay!
I will be researching more. I won't be able to do my own repair right now. Too hot to be crawling under the RV so I will wait until it cooler and can have my son help. In the mean time I will be searching for videos to remove the tank and connections. Thanks for all the advice. It's help full and I don''t feel so alone knowing I'm not the only one with this problem or feel the same way about it.