Dewderonomy
Grandmaster
This isn't to increase storage beyond the max that currently exists. Instead it would allow people to upgrade the storage in their houses to "Small", "Medium" or "Large" storage. Each one would have a preset storage limit, and you would need to buy a Small to get a Medium, and then a Medium to get a Large (if you so wanted). This would effectively turn the storage capacity of your house to the new storage package.
For example, if you had a small house but wanted a little extra, you could get a Small upgrade, which may count as L-shaped storage. Or if you wanted even more room, get the Small and then the Medium, which might be Tower capacity. Likewise if you wanted, say, castle-size storage, you could buy all three and have a small house with the storage capacity of a castle. This way people can put the money into having more storage even if they can't (or don't want to) get a larger sized house. This would, in turn, make having the cellar item more meaningful for those who don't have a max-sized house.
They could be priced at 500K, 1 mil and 2 mil, respectively.
For example, if you had a small house but wanted a little extra, you could get a Small upgrade, which may count as L-shaped storage. Or if you wanted even more room, get the Small and then the Medium, which might be Tower capacity. Likewise if you wanted, say, castle-size storage, you could buy all three and have a small house with the storage capacity of a castle. This way people can put the money into having more storage even if they can't (or don't want to) get a larger sized house. This would, in turn, make having the cellar item more meaningful for those who don't have a max-sized house.
They could be priced at 500K, 1 mil and 2 mil, respectively.