A good bulb will cost me about what I paid for the ballast, reflector and socket combined.
It will sell to someone looking for something dirt cheap on eBay; the same type of person that would buy the eBay bulb himself. It will sell for much less than a new setup and the buyer will understand what he is getting. My descriptions are accurate, detailed and honest. It will not be a rip-off. It will be a lower quality setup at a low price. It is the same concept that works for all goods exchanged at all levels. It is not the type of setup that will appreal to an experienced or serious hobbyist.
Having the bulb makes it a complete setup. That is more attractive to a potential buyer and will increase the final price of my auction. The only way the budget allows me to be in this hobby is if I use some of the knowlege and experience I gain to turn a profit on a setup I rehab or components that I piece together.
It has worked well so far and all of my buyers are quite happy with the values they get. I have sold at least 50 aquarium-related items (or complete setups) on eBay and my feedback is 100% perfect with over 650 transactions over 6 years. I predict this MH lighting will find a buyer that will be comfortable with the balance of price, quality and service that he will receive.
I hope this clarifies my need for a cheapo bulb and satisfies your desire for an explanation of my motivation.
Now, does anyone have one?