theses were sold out because they were only 130$ on sale. they have been sold out for quite a while now and just now are available again. if you buy one just watch for them to go on sale and have them price match it for you in store. you have 90 days for the price match/return policy.
to try to break it down. the 4 amp battery is 110$. the 2 amp battery is at least 50$. the dual port charger with usb charge ports is not for sale as far as i know, but a single port w/o usb is 50$. so this is at least a 210$ package. so basically your paying for the two batteries which if you bought them not in a kit would not come with the lsa option. instead they would have a three warranty. so your getting the sla option and charger for free with this kit and maybe some money back later.
batteries and charger offer the sla, so just get them registered as soon as you have them and your set for life on two more batteries and is a perfect upgrade for those who bought the 2 amp battery/drill kits. i like the 2amp for lights and smaller jobs that don't the 4 amps or added weight.
the only way to get the lsa on batteries is when bought in a kit, that's why this qualifies.
RIDGID
18-Volt Lithium-Ion Dual Port Sequenchal Charger Kit with (1) 4.0Ah Battery and (1) 2.0Ah Battery
Allows you to dock two batteries conveniently
2 USB ports allow you to charge your electronic devices
Wall-mounted design allows you to free up counter space
$159.00
https://www.homedepot.com/p/RIDGID-18-Volt-Lithium-Ion-Dual-Port-Sequenchal-Charger-Kit-with-1-4-0Ah-Battery-and-1-2-0Ah-Battery-AC840094SB/301404315