When did matches cost half a crown a box?* This was the retail price of the first friction matches fit for practical use, which were invented in 1827 by John Walker, an English chemist. They were sold in tin boxes of fifty, each of which contained also a loose piece of glass paper for striking the matches. The price was later reduced to a shilling. Among the early imitations of Walker's matches was a brand called 'Lucifers'.*
*The context of this question is that in 1938 when this question was published half a crown (12.5p) would have sounded ridiculously high. A shilling is 5p.