Okay, how about:

Thank you for your recent reservation. We look forward to your upcoming visit with us. We have taken note of your request and if we still have availability upon your check-in, we will try to accomodate you. blah, blah, blah.

We have always requested an upgrade in the special request section of the reservation and we have always been upgraded with no charge and at 5* hotels.

I find it rather blatant to be told it's gonna cost ya so pay up or stay in the room you have booked.