Whether the cheaper bulbs work ok or not depends a lot of the quality of the power available where they are used. The better quality (and higher priced) bulbs have circuitry to compensate for low and high voltage, for lots of ac (alternating current) ripple in the 12vdc. Battery current is clean but often low as the battery discharges or other devices go on and off. When the RV is plugged to shore power, the converter produces the 12v and many of them provide very "dirty" power, especially the old Magnetec 63xx series and its competitors. High voltage can be as bad as low voltage too.
Outfits like Revolution and Ming distribute only the best quality and they back the product 100%. Others may be anywhere from crap to nearly as good. I know the folks at rvledbulbs.com have tested a variety of off-label Chinese imports and they offer those that performed reasonable well as a lower priced alternative to the Revs and Mings. I've used a few with decent results. Your mileage may vary, but rest assured that rvledbulbs.com will back anything they sold. I've been doing business with the parent company (ocalahitch.com) since 1996 and know them to be fair and reliable.