Found a bug with the GUI.
When buying a lot and selecting plastic as the lot type. It buys the Residential lot type.
Fixed.
How about build ratings? People rate your build, and your sales become scaled depending on that rating, e.g. a build rated 1/5 will receive almost nothing from sales and a 5/5 build will receive much more.
That's do-able, but could be abused easily. Currently I have an automated lot valuing system in the works, where it modifies your lot based on the value of the lot compared to that of others. Lower value lots just basically suck; lower income, decaying supplies, etc. Eventually there'll be more logical penalties, but that's all there is for now.