We donated ours to a local thrift store when my son was about nine or ten years old. A few days later, my husband and son were at the store looking for shorts for my son and said they saw the kit-sets a few days later at $2 for the lot – that was half a dozen mostly complete sets. Interestingly, the complete set of Lego jumbo generic blocks we'd gotten him when he was a toddler were marked at $5 – and, someone from my church nursery happened to buy them for the church while my husband and son were there (if we'd known they were wanted, we'd have donated them to the nursery).