As a long-time (and happy) user of Motolights, I can tell you that you get what you pay for.
Although the bulbs look the same they are not the same as the ones that you can purchase at Home Depot or other lighting stores. Yes, they can be used in a pinch but the beam pattern is different.
Think about all the abuse a light takes mounted so close to the road surface. Sand, rocks and pebbles, constant moisture hitting it at 80mph. These lights are built battle-tough and don't leak. And they're guaranteed for life. Not just the lamp, but the whole assembly. So when I noticed the reflector was degrading on one of my bulbs I called them to get a replacement lamp. She ended up asking me all sorts of questions about what type of wiring the light had, while I was wondering why since I just needed a replacement bulb. She determined that mine had an older-style wiring harness that used a different grommet setup to seal out moisture where the wires went into the light. She sent me a whole new wiring package and the updated seals.
I called them another time when the small spanner wrench that's used to remove the retaining ring lost one of its pins. It turns out the customer service lady I talked with is the one that builds the wrench and was glad to hear me call to tell her about it. She sent me out a new one, no charge of course.
YMMV but I'm a happy customer and any bike I own will have Motolights mounted on it. Again, let me say you get what you pay for.