Well if you are from UK, you can answer that question the best. Do you see businesses advertise with co.uk or .com and .net. If you see a good number of co.uk you are ok, but start slow buy 5-10 at the time if you generate the list of 100 pick 10 best ones and go after buyers. Do NOT buy more until you sell at least 2 you got. Let's say you spent 150$ on the 10 names and you sell average 300$ each now pick 10 more for 150 and put a side 150$ for future high end domain.
Best of luck