B.C.
If you want something that's going to last any amount of time - stay away from technology - it's constantly breaking and is outdated in roughly 2-3 years.
A bench near the playground with a plaque on it might last for 15-20 years.
A display case will last many years.
You could plant an AWFULLY nice tree for $600 and if it's a slow growing hardwood, it might live for 50-75 years.