I heard this too. The bags will be available from Ryanairs website only.
The bags are due to sell for just 1p. But by the time you add VAT, surcharges, P&P and the £7.50 credit card surcharge then they will be about £40.00
I have just bought a bag specifically for Ryanair carry-on. Ryanairs limit is 55x40x20. The bag I have just bought is 51x40x20. IT also has trolley wheels and telescopic handles. It also has its own inbuilt lock.
Available from Dunelm Mill at just £9.99.
Steve