Relative value of money is always a tricky one ... and I always find it best to contextualise it rather than index it.
Siegfried Sassoon, before the First World War, had an unearned income of £450 a year, which was insufficient to enable him to live as a gentleman and hunt 5 days a fortnight through the winter, but not by all that much (see Memoirs of a Foxhunting Gentleman). A modern equivalent would, I guess, be a private income of about £50,000 a year.
38 shillings, or just under £2, was therefore a little under half a percent of this. So, say, about £250.
That's not far off Hallmark's figure; and Rockford's contextual figure of a week's wages for a miner also feels about right (thus miner earning equivalent of £13,000 a year ... seems about right ... never was a well-paid occupation).