If you go on the greyhound data site look in classifieds there are puppy adverts there. Some are fairly young pups others are older ones 6-12 months. Make sure you can the area to UK and are not lookinh in the Irish sales list.

Here is the link to the UK pups scroll down and you'll find some reasonably priced ones.The first ones are extremely expensive but there are some cheaper ones further down.

Greyhound Pups for sale