DIY HQI-----worth the effort???

[scavdog]

I have been debating for quite some time on what kind of lighting I am going to add to my 100 gallon prop system.
I am planning on sandwiching the existing 400 watt Iwasaki with 2x250 watt 10k HQI's.

2 PF0 Pendant setups with bulbs and dual ballast will set me back close to 700 bucks. I am, however, entertaining the idea of a DIY HQI.

What are the costs for such a setup? and is it worth it in the end?

Thanks for any input.