I've always been a believer that there's a high cost to low prices, and that you don't always realize it up front. I live it myself with some of my own purchases, and sometimes, you decide that the savings was worth it. Sometimes, it isn't.
To make this post a quick one, we ended up shipping six lamps to the client. Two were bad out of the box, one burned out almost immediately, and one had a loose lamp base that prevented its use. Two worked just fine. We also sent two Panasonic brand lamps, and both of those were perfect in terms of condition and performance and were slightly brighter, to boot.
I completely understand your pain in paying $350-500 for a light bulb and that a "compatible" for $100-200 less can be tempting. Just be aware that there's often a high cost to low prices, and in this case we both paid dearly.