The Value of a Gift

My Granddad built the house in which I grew
from birth to adulthood. Not solo, but with
builders working under him. A master plasterer,
he turned his hand to many trades. Three bedrooms,
end of terrace and two loos (unusual back then)
and solid as a medieval castle. (You could not
knock a nail in any of its walls, was his
proud boast.) The total cost: one hundred pounds.

My granddad gave me once a golden guinea
to keep safe. Years later I would lose it
moving house. That would have pained him, but
by then, granddad had died, and dad had learned
the house was still insured for that one hundred pounds.
(Granddad would never trust insurance companies
or banks - Low, robbing buggers was his phrase for them.)
By then the house was worth around six thousand.

A conundrum for you: what was the value of
my granddad's gift to me? A guinea - one pound
and five p in our new money? Even then
the coin was worth far more than its face value,
but to me the value of a gift is what
it cost the giver. Granddad, seemingly, thought he'd
given me a coin worth one per cent of what
the house was worth - or sixty pounds just then.
Half that, maybe, back when the gift was given.