Can get 180Wh worth of Dewalt batteries (+ charger) for under $100 right now at Home Depot with Holiday promos. The 6 Ah XR in that bundle would have a far superior Samsung 30T 21700. 10 per pack. 5S2P config.

There's also value in utility. Especially if you are invested into a decent power tool platform. (Milwaukee, Dewalt, Makita) Your money goes further if you have a bunch of devices that can share the same battery. I run as much stuff as I can off 5.0 Ah Makita packs I basically paid no more than $7/Ah on. (Buy sales, batteries get super cheap)

Wouldn't exactly call used Eve cells that you might have to rebuild sooner rather than later a good value long term. They have a paltry 7.65A rated cell with comparatively low capacity, probably closer to 2-2.2 Ah since its a refurb/used 18650 from a 3rd rate manufacturer.

Samsung 30Ts blow that Eve crap out of the water. 35A cell, up to 70A @ 18V in 5S2P.