I built a six inch reflector many years ago. Ground the mirror myself. I wouldn't recommend grinding your own mirror today - the prices on mirrors have really come down, and the learning curve to grind your own is steep - your first mirror is never flawless.
That said, if you decide to build your own from purchased parts, go with an eight inch mirror (it's sort of the same as the argument about a six inch or eight inch jointer).
Once you build the telescope, you then need a mounting, and a tracking device. All told, it can be expensive.
My problem after building my telescope was that I was much more interested in building the telescope than in using it. I found looking at the sky fairly boring.
Mike