As most of you know the Bulb for the Ruby (Sony VPL-VW100) is a "Cermax" style/brand xenon bulb. (Sony LMP-H400)
Here is a supposed picture of the bulb itself
Here is one in the housing/heatsink
Although the going rate for Bulb with new housing in the US seams to be about $850 you can knock $200 off that price going overseas.
The real question is how much can you get "just the bulb" for as many D-ILA owners have been remounting just the bulb in their old housing/heatsinks for a few years now.
What we learned was you could go to a higher wattage bulb and extend the life of the bulb and not experience as rapid of a dropoff in light output in the beginning. Basically the power supply compensates for the higher wattage rated bulb and the bulb size/form was identical from 400 w - 500w. which allowed the 500w bulb to fit into any of the G series projectors/housings.
I'm pretty sure the same is true for this bulb too and the housing looks even easier to seperate and reseat a new bulb. just a clip on top and bottom?
Anyway, now there are many places to buy Cermax bulbs retail so finding replacements should be pretty easy. Someone out there knows a good cross reference number for the identical bulb to mach up with Sony's "proprietary bulb" model number. Or it may be time for some to do a little experimenting with higher wattage
Ruby bulbs for under $500? entirely likely.