When my land-line said I needed to change the battery, I discovered it only takes AAA rechargeable ones. So my question is "how do I recharge these ?" - ... or "do you sell these?, and what is the cost ?"

You need a charger that recharges rechargeable batteries. You can get that at best buy

You probably can use just regular AAA batteries but I would suggest to use lithium type because they last a heck of a lot longer

Got to buy a new charger and some batteries

Im not sure what you need specifically. But im 90% sure any AAA batteries will do. Now if you're specifically looking for rechargeable batteries, i suggest looking onto best buys website for both availability of item and price if they carry it in stock at your cloest best buy. One other option is going in person to find what you are looking for.

Best Buy carries those batteries and chargers. Don't know the cost.