I had a private scan for 12 weeks with this little babe and also when I was having my daughter. I went to the Fetal Medicine Centre in London for the scan. It was, as it had been last time, a great experience and I came home with a stack of photos of baby, including a couple of 3D ones which neither hubby nor I expected to get.
The FMC do a range of scans from fetal viability through to general pregnancy well being and all their prices are clearly shown on their website. I would recommend them to anyone.
Good luck in whatever you choose
Fetal Medicine Centre