I've found buying cheap/off the internet tends to be a crap shoot. The vast majority of those purchases resulted in inferior bulbs with diodes that wouldn't light. You get what you pay for, IMO. I've learned to ask the right questions to get what I want:
- What's the kelvin number? (determines warm vs cool vs daylight...industry terms for color output)
- What's the lumens? (brightness)
- Is it dimmable?
- Is it going in an open or enclosed fixture? If in an enclosed fixture (like a lot of RV lights pictured in post #10 above) the bulb needs to be approved for an enclosed fixture or it'll go bad before it's time. They still produce heat & that heat needs a place to go.
I've had the best luck with vendors at RV rallies that let you take bulbs on trial. They're most willing to help you find what works best for you. M4 (as previously stated) sells reliable bulbs as well as Jirahled