Looking at their website https://www.paypal.com/cgi-bin/webscr?cmd=_payflow-gateway-overview-outside , Paypal Payflow allows you to use their framework in conjunction with your own Merchant Account which you got from your bank. In the end, the advantage of the Paypal Payflow over a Business Account is that you can to use your own Merchant Account and you get payment from your customers in your bank account sooner than using Paypal's full service account.
I don't think they should charge that much for that. I know of companies don't have monthly fees and a cheap one time set up fee.