win 1500 rupees with just an idea

i am insperation less so ....... i want a building on my lot max area is 25x16
the idea's that won't win: hotel,farm,shop,restaurant

1. has to fit on 25x16
2. no possibilty to dig (underground animal farm)
3. all materials are allowd
4. low possible cost
5. build has to be possible for an amateur builder

if you give me the idea that i will build you win 1500 rupees

"Minecoke" Wool and redstone vending machine

series of cobble generators you then give people perm to use them for rupees of course
or a roller coaster

A auto wheat farm?

There's always the option of building and enchantment room. I build my original one out of obsidian and glowstone before moving it to my new tower.

Light sensor.

Skyhigh building.
Automatic lightning system.
Make your own face out of wool

Some sort of statue maybe? Your own skin in a pose, as heroic as possible, of course! Or the classic giant creeper

Old idea, but nice, none the less, a double helix of glass, one side water, one side lava.

Build a little race track, get 2 pigs and 2 saddles.
Pig racing!!!!!!!!!!

I'd go with this idea why look at something cool when you can race pigs!

I say go with 333's idea.