Can I add two things,
It's partly how you spin it!
When asked on one occasion what he had done, DS said he'd had a film night, set off an explosion, gone shopping with a mate. The richer kids were wildly jealous, as they were usually over supervised. ( yes, there was supervision esp of the explosion
And on another occasion, they were asked to keep a holiday diary. Most people had eg two weeks in Thailand, me with elephant photos iyswim. DS and I had put together a scrapbook diary for almost every day, with drawings, pictures, pebbles, shells, wheat where we had gone across a wheat field, we made brea to link with the wheat, brochures where we had gone to a free museum, yes with a post card. We covered the scrapbook and it bulged. It was the most amazing record and he still loves it, as do I. He won a lot of respect from it.
Secondly, the Internet is your friend, as are charity shops.
You can pick up musical instruments for very little and you and they can all learn together, using you tube. Much more fun to do it all together.
Ditto with modern languages. Decide that you are all going to learn Spanish , easier than French, do the learning and once a month have a Spanish day, talk nothing but Spanish, eat Spanish, dress Spanish...
If you are near a beach, get them to study it as well as enjoy it.
Spoon fed kids may have less initiative.