This UK title reprinted the Amercan itle of the same name and each issue came out a few months after the American original.
Issue #12 reprints the mega American issue that was the first appearance of Harley Quinn. The UK issue came with a fre gift Batman badge which is often missing (and if missing there's usually a sellotape tear on the cover!). There's also a poster at the centrefold which the US edition doesn't have.
Hard to put a value on on this issue. £100+ wouldn't surprise me.
Note: some PR issues may have no value. Selected issues in FN, VF or VF/NM may not exist in some titles.