i usually get my bank to match, or beat the lowest rate offered elsewhere. the only time i have ever been charged fees is when i broke a fixed rate early (early repayment penalty). i even had an arrangement for a floating rate mortgage with a discount of .5% from standard book rates (i doubt they would discount as much now).

If you go to another bank, not only would you probably pay no fees, you could probably get them to cover your solicitors fees too.... at least talk to another bank before accepting any fees @ BNZ