Costco was a bust, they only have Kirkland now.
Went to Total Battery. The battery listed for an e30 is very small, needs custom work to 'fit it' and a new negative cable longer to reach. Was $236 with 3 year warranty and weights 38lbs. The factory replacement from Total Battery (own brand) fits perfect, 3 year warranty (free replacement) then prorated warranty after that, weighs 42lbs and was only $116.
So I went with the cheaper one.