Is there a good cheap place to buy optimas?

They now make a bluetop battery for sailboats.  the
deep cycle version is the exact same as the yellowtop,
but it has wing nut terminal fasteners instead of the
typical studs.  The optima website is in transition to
a new site and there is no info on it yet.

I put my optima in 3 years ago.  It does not hold much
of a charge anymore.  I have run it to the red many
times.
steve