Blood test to predict gender uk

I've seen all the us ladies talking about this and it is available in the uk from about 7 weeks although costs around £179. Although reading into it if you have had a recent miscarriage although it does not specify time. Bone marrow transplant or have had a blood transfusion it is not accurate. So no good for me as I've had a blood transfusion. Also a lot of money in my opinion when you can get a scan at 16 weeks for cheaper or just wait till 20 weeks. Thought some people may like the info though.