Tips and hints:
* Instead of starting with a Farmhouse (hoping to sell for profit) with the currently available workforce, start with a structure building (I prefer the Sawmill since material aren't sustainable like workers). Train two workers during the time of construction and go for the Manor for double profit.
* Once you sold the Manor, forget it to the rest of game and focus on the other 8 lots. Eventually you are going to keep 4 painted Mansions and sell 4 Mansions (might need a single upgrade according to cash flow).
* If you are intended to do a speedrun, $75k investment towards the efficiency of Workshop is the most valuable investment, make that ASAP.
* Houses near structures get negative appeals. Use it to your advantage. Build structures near houses you intend to buy (if possible) and avoid building houses to sell near them.
* Painting 4 houses and demolishing the structure buildings towards the end gives net +20 appeal. You need to paint only 4 houses, no lighting required (lol).
* Don;t sell two houses of same kind (Mansions I guess) at the same time: chances are callers asking for bargained prices (you might be short of a last 100k for extra half a minute: happened to me).
* Chances are there are better strategies to accomplish this goal quicker and I'd love to hear your opinions. Thanks for watching! :-)