Hello
@GeorgeIP, welcome. I have no idea about costs or how to go about something like this but I would say that a diagnosis does not actually make a huge difference in the first instance. Providing your GP has ruled out all other causes of memory loss then waiting will not create any further problems. Depending on the kind of dementia you wife may be diagnosed with there is very little in the way of medication that will be prescribed and unless you are struggling with her care needs, service will not see a need to become involved. Maybe it is better to keep your money for another time. This is just my opinion however, you may feel very differently and that is absolutely fine. Things you could do now would be to get LPA for finance and health and welfare sorted, get your wills drawn up and familiarise yourself with how the various types of dementia progress so you are prepared for the future if and when your wife gets a diagnosis. Just recently I read on here that dementia is a marathon not a sprint, this is very true indeed.
Please come on here and have a read of the various forums and ask any questions you have, we are all happy to offer our input.