depends on the redemption you select, but you can get over 1pence for each one, can be as much as 2p. Depending where you buy them from, you can get them for 0.75p (0.0075) or if you use part pay as cheap as 0.55p (0.0055). I value you them just over 1pence, but it all depends on the flight taken... Example 9,000 avios from LHR to a number of european places plus 35 which is normally a 150-200 return ticket... while MAN to BLL is bookable last minute for 250 to 350 pounds or the same 9,000 avios (35pounds cash). If you were going to fly with a low cost carrier, then it's not always worth it. Info above is 50% mine and 50% from headforpoints.... If you are using your avios abroad on 5th freedom flights or partners - this is when you get great value.... Example - AMS (easy to get to with a low cost carrier) to Hong Kong 60,000 miles and less than 100 pounds return - business is 180,000 miles and 101pounds return Another example is 50,000 miles plus less than 40 pounds from Europe to Japan (return)... When you can get 20,000-30,000 for free for signing up a credit card... you can see you get great value... it's like 13pounds from the mainland states to Hawaii as well... Sorry a bit more info than what you wanted, but hope this helps...
theres no actual value but you can buy 1000 avios for £31 on their website
18000 points for London to rome is possible. Less than 1p per point on average in my experience
What is a typical value of Avios points?