I would go to your local dealer and test drive. They may have used Pfaffs with dual feed that they could sell you with at least a store warranty. I've not heard any negatives about the new 7 series Berninas. I've had tons of issues with my 8 series, but that's a completely different machine.
One of my most favorite Pfaffs with dual feed is a 1471, which can be bought for less than you've been offered for the 7530. I also really love my 1222 which is a wonderful machine. Any new Pfaff is currently under the SVP umbrella and is no longer made in Germany. Keep that in mind.