Of course a couple married for 50 years have no need of gifts. I wish something like this had been acceptable when we married, almost 50 years ago. People bought what they thought we would like, so we mended up with several ugly coffee sets, numerous mismatching casserole dishes, etc. we were not ungrateful because in those days you took what was going with a smile and a thank you letter.
How much more sensible to contribute to a honeymoon, as happens these days, or to a safari trip.
crun anywhere from £25-£50 depending on your circumstances.