Minas Tirith specifically, and Lord of the Rings in general, is one of the most popular (and common) subjects on LEGO Ideas.
At 9950+ supporters, Lord of the Rings Set: Minas Tirith has the distinction of being the first LOTR based project to reach review.
I know at least one Brickset commenter that will be thrilled to see this project reach its goal. ;)
If you love Minas Tirith but are "supporting on a budget", I must recommend this tiny Tirith which is almost at 1000 support.