It's very unpleasant find about forgeries, now, when I purchased 1 metica and 20 cent coins for 150 euros. I miss two of them now. I still believe it's some catch, at least with original dies, so nobody can ever tell the difference.
They were cheapest 4-5 years ago, I saw at least twice sets for about 100 dollars on ebay. I bought first, 1 centimo for maybe 30 dollars in 1999 or 2000 and it was first I personally saw on the internet. Price has dropped after, but then rose quite much again now, as actually whole numismatics. That's why I wanted to finally complete it.
Didn't know also for Libyan 1979 set, I've got few sure originals in VF-XF and they're, as Afrasi said, exact as the UNC pieces bought recently. From weight to everything...just checked.
It is not scarce in our hobby, however that original dies are used later for rare coins. Good example is Yugoslavian pattern of 25 para, 1 and 10 dinara 1979 that even have original mintages od 15-20 stated in Krause. I own all and they are sometimes available in local auctions for not more than 100 euros each. first examples, sold in 80s were costing about 2000 DM, which, I would be free to compare with at least 2000 euros today.