Indeed, Wally is WalMart. Deals on batteries can be found at big box auto stores, Costco, Sam's, KMart, etc. If one intends to travel out of local region, then nation-wide sources of tires
, batteries, etc. should be considered.
Here are some thoughts to consider before spending extra $$ on AGM. It's your money and your choice:
1. AGMs are effectively just a lead-acid battery with the acid in a sponge instead of a puddle.
2. Most (all?) batteries are composed of smaller cells, but the cells may have different construction, like designed for starting or deep cycle or something between. That's why it's not good to mix battery types in a string. AGMs seem to be dual purpose because starting is mentioned on specs and description, but that may be less of a drawback than with a flooded dual purpose battery.
3. Although they outgas H2 less than the flooded batteries, they still outgas. Post from another RV group:
"The NEC made no exceptions for the battery venting requirements in RV's.
The AGM battery manufacturers are careful to state the batteries must be vented.
If you can find an AGM battey manufacturer that has an exemption for venting, please post a link. You'll be the first - no one in the past has found a manufacturer with an exemption."
That said, I know of many folks who have mounted AGMs inside van campers, etc., even on their sides (but not upside down). I also know of folks who have mounted flooded batteries inside, as they used to do in some vehicles like VW. I would do the former, but not the latter.
4. AGM's come in smaller Amp-Hour capacities than typical flooded battery of same nominal size. OP was looking for more power, not less.
5. AGM's reportedly last longer than flooded, but not as long as they used to. They were having troubles with improper charging systems damaging them; reportedly they were redesigned to tolerate a greater voltage range but in the process, they lost some expected life. I believe they also fixed the thermal runaway problem that was happening with the early AGMS.
6. AGM's will tolerate a lot faster recharge rate than flooded batteries.
7. As to economics, I don't believe an AGM compared to a series of flooded batteries is going to prove in. It would be more convenient, however, not having to replace battery for longer number of years. Add to the equation that the warranty on the AGM will expire much sooner than a series of warranties on flooded batteries.
8. Having had a battery stolen from the tongue of my Scamp
, I was darned glad it wasn't an AGM -- That would really affect the life-cycle economics... If one's battery is mounted inside, it would be safer and of less concern on this score.
When the AGMs start dropping in price and start replacing the flooded cells, then I will consider them again, but for now I will continue to use flooded cells. YMMV!