A story paper of limited collector interest apart from an unusual run of 21 issues featuring reprints of Superman, the first time the character was published in the UK and only a year after his debut in Action Comics #1, June 1938 (the most valuable American comic book. Arguably the first UK appearance, technically speaking, of Superman is in the ad in issue #771 showing the front cover for issue #772. The date was July 29th 1939, just 13 months after the debut of Superman in Action Comics #1 in June 1938. A copy sold for £50 in a Vault Auction in May 2004. The run from #772-792 includes four with a Superman cover appearance with art by John McCail. A set sold in the UK in 1994 for £1,500. Another set fetched £1,730 in June 2001 (Comic Book Postal Auctions). I remember a San Diego Comicon in around 1994 had a set stickered at $6,000 but it didn't sell at the show. In June 1996 the first issue of the run #772 (5th Aug 1939) sold for £152 on eBay UK in VG condition with rusty staples and tanning edges. A GOOD grade example of #788 sold on eBay UK in Nov 2007 for £107, sold by the inestimable Mr. Stuart Dexter (lindex). In June 2004 a lot including 18 of the issues with 2 (I think) of the Superman covers in Good to Very Good condition sold for £618 by Comic Book Postal Auctions.
The non-Superman issues are difficult to value as individual issues as they are usually sold as bound yearly volumes. Values are suggested in this Guide for the 20 Superman issues.
STOP PRESS! The second run of Superman in Triumph issues #807-814 sold with Comic Book Postal Auctions in their Nov 2009 catalogue for £225. There are no Superman covers on this run.
#814 was the last issue of the title owing to war paper shortages. The title amalgamated with Champion.
Dec 2017: a set #771-792 from the Bob Monkhouse Archive fetched £1,220 in the Comic Book Postal Auctions sale.
Note: some PR issues may have no value. Selected issues in FN, VF or VF/NM may not exist in some titles.