My partner Debbie and I have 30kg of stuff.
That's a handy constraint, in that you both can acquire arbitrary amounts of knowledge and skills without any impact on the scales.
Riffing off of Aristippus' advice to give one's children the sort of assets which would swim out of a shipwreck with them, and the original blog post's mention of books, I'd say (having learned the hard way myself) that for disciplines which are difficult to learn from books, it's worth paying more for better teachers.
-Dave