They had a decent enough reputation in the dressage circles i moved in when in the UK and there was a horse close by to us who was out winning at medium who'd been a recent purchase from there and the owner always commented on how pleasant they'd been to deal with.
Just had a look on their site and theres certainly some nice looking horses on there.
You probably can buy cheaper yes, but they're a professional place to deal with and good facilities to try out etc. I'd certainly take a look if i saw anything i liked and while ive never dealt with oldencraig in regards to sales, i have about livery and they were really helpful
Also how about looking at www.globaldressage.co.uk - Kay is fab, really knows her stuff and will be able to find your friend exactly what she wants, even if she dosent have anything in thats suitable at the time.
A lot of their horses have done well so it would certainly be worth a look for your friend. Only thing I would say is not to take an awful lot of notice of what is said on the ad's on the website!
A friend went to try a 4 yr old that had just been backed, it had only been sat on 3 times before that so you can imagine it wasn't exactly established! The next week they had it advertised as novice working elementary and saying that the judges loved it! That put my friend off of them entirely!
Someone else I bought a horse from them 3 years ago and he is lovely!
also remember to ask where the competition record has been gained as a lot of the O'craig horses only compete at O'craig with their professional work riders on board. If it is a horse with competition record at other venues and with a variety of riders I'd be more confident that it was suitable for a good/average non-professional rider.
also make sure wherever she buys that the horse has a full 5* independent vetting and X-rays and blood test done. If they are spending that amount of money - 8k+ - then the cost of this is worth it and the risks will be lower.
I'd also make sure that you goto see the horse and then turn up without notice a 2nd time to look again prior to the vetting, whereever they decide to buy. You can find out all sorts of interesting things by turning up unannounced ;-))