I don't know what your definition of reasonable is but if it is around 250GBP you might want to have a look at AndroidIce.co.uk. And if you wait until October (
)this one looks very interesting:
https://www.androidice.com/blog/mgzt-android8/
Support is good and seller is trustworthy.
For around 170GBP eBay offers some units but I don't know these sellers or the quality of the products:
https://www.ebay.co.uk/itm/Android-8...D/202760977111
If you really want it dirt cheap and like to gamble, you might want to try this:
https://www.aliexpress.com/item/33015222043.html. The only guarantee you have is that you will not have any guarantee that it works.
HTH