A year ago I wrote a summary of what I had spent retrieving documents.
One section was devoted to the UK General Register Office, from whom I had obtained several birth certificates and a marriage certificate. Each certificate cost 7 pounds, and last year the rate of exchange was 2 dollars = 1 pound, so that was $14 apiece.
The rate of exchange is back down to $1.50 per pound. Most of this drop has occurred within the past 90 days.
So now could be a good time to make purchases from the GRO and UK National Archives.