In communications,
jeff_wisnia wrote:

SNIP previously quoted material

But those $19 fixtures are usually pure crap and fail rather quickly. If
the present fixture and its sockets are in good shape I'd go for
replacing just the ballast.

I see some cheap fixtures last a while, especially if suspended on those
chains that come with some of them to allow the cheap ballasts to cool
better.

However, I have seen shortened bulb life, reduced light output and
reduced energy efficiency with those cheap fixtures.

- Don Klipstein )