I thought that Coachmen was using 'L' to designate 'Lithium', but it seems like the models have 'Li3' or 'Li' in it instead.
I'm seeing more than $25k price differences between non-Lithium RB's, which is expected as dealers have differing strategies to maximize profits. When I bought mine, some dealers were asking 50% more than others for the exact same (new) van.
Also, online ads are terribly inaccurate at times, even for legitimate dealers. They tend to copy/paste descriptions and features, often unintentionally misrepresenting vans. A dealer on RVtrader has an Li3 advertised as having AGM batteries, for example.
If you want lithium, look for the 'Li3' logo up by the front doors. Otherwise - don't pay a $25k premium for a non-lithium van.