As a follow up post...
Fortunately, Wal-Mart did have 4 batteries on the shelf. They appear to have abandoned the dual-purpose line, which was a little disappointing, so I ended up with 2 each starting batteries (house) and 2 each deep cycle batteries (24V trolling). I can easily get by with one house battery but since I have room and weight allowance, I still prefer having 2.
Starting battery: $70 each
Deep cycle: $75 each
The deep cycle batteries I returned as a core had no price labels on them, but the dual purpose batteries did. They were $65 each when I bought them in 2011...so a very minimal price change.