I wanted to be able to view housing prices quickly - so I made a spread sheet. Hopefully will help save some time. Cheapest house per tier highlighted in green. Please let me know if there are errors.
I'm pretty sure the smallest rooms (3000 gold ones) allow for two trophies and also up to 50 furnishing items (I will admit I could be wrong about the furnishings).
However, I know that the small rooms allow for two trophies because I currently have 2 trophies displayed in the Rosy Lion.