All batts in USA are made by 1 of 3 outfits: Johnson Controls, Exide, or Interstate. Naturally, all 3 supply various models of Everstart to WM.
I buy from a "local independent" who sells generic batts made by Interstate. In Feb 04 I paid $32 for a new F150 batt (included tax and exchange) and it's still going strong. Same batt sold by Wallys for $60-70.