Interest in this title has perhaps wained as avid collectors die off. There is still nostalgic appeal for the 40s and 50s issues though and very early issues show up from time to time on eBay UK. High grade runs sell well, particularly war-time propaganda issues. Rather than try to arrive at values for individual issues, it is perhaps sensible to look at complete years as this is how the majority are sold. From that it can be understood that individual issues are anywhere between a pound and a fiver each depending on age and condition.
The free gift Mask with issue #1 is incredibly rare - the single know surviving example sold at a COMPAL auction with the comic for £330 (£363 with Buyer's Premium) in Dec 2004. Usual brilliant sourcing and research by Malcolm Philips. His COMPAL business has probably sold more issues and complete years than any other and is keeping interest in this title very much alive. Impossible to say how much value the free gift mask would add now to issue #1 now - £150-£200? A Good/Good copy of issue #1 with no free gift sold on eBay UK in Nov 2007 for £51.43 by Mr. Phil Shrimpton, fine purveyor of such comics. The free gift with #2 was the Jumping Frog which showed up again in Dandy #2 four years later.
For in-depth study and cataloguing of this title, you could do no better than pick up Derek Adley's fabulous labour-of-love guide which pops up on eBay UK from time to time. Heavily researched and hand-typed (no computers back in 1982), it is simply marvellous! Well done sir!
A copy popped up on eBay UK in Mar 2014. The buyer had a starting bid of £1,500 and claimed in his description that on the internet it had a value in excess of £7,000...well, not valued to that level here by me! What rubbish you sometimess see on eBay UK.
Note: some PR issues may have no value. Selected issues in FN, VF or VF/NM may not exist in some titles.