Just checked lot sizes per tax records for all MLS sales on Rising River. Found 12 homes with 9 of them having lots between 10K and 14K. There was a 16K, an 18K and a 20K also but all neighborhoods have a few exceptional lots. Lot size on Rising River house in question was 12,007 sq ft.
Just checked lots sizes on Silver Gum and everyone was between .5 and .65 acres (that is 22,000 to 29,000 sq ft). The homes were also several hundred sq ft larger.
Throw in the poor location and to say the Rising River sale was a 2000 price is a real stretch. Not saying it wont get there but its not there yet.