When we first purchased our RV, these bulbs were sold in RV stores for $5-$6 a piece.  The parts person would take one out of a sack and hand it to you.  NO  WAY.  Such bulbs should not be touched with your hands.  The oil from your hands will cause them to overheat and break.  One should hold them in a tissue or better yet wear a rubber glove to install. I have sense used two bulbs.  I broke one just trying to install it in the fixture.  This could have been my fault or not.  Nevertheless, the bulbs appear to last as long as others.