I don't think the first moss is Sphagnum, it looks to have some visual shimmer/shine that makes me think of Hypnum or another of the mosses sold as 'sheet moss'. It should start growing again if you give it some light and keep it moist with clean water. IIRC the grower/author Lance Birk's preferred Paph mix is coarse silica sand, 'sheet' mosses like Hypnum, Thuidium, etc., and fir bark. Unlike Sphagnums, though, I wouldn't recommend using this alone or even as a substantial proportion of a potting medium.
The Mosser Lee stuff I wouldn't recommend at all for most orchids, it is real Sphagnum but usually of low quality. I do sometimes use it with coco peat as a cheaper and more sustainable alternative to sphagnum peats in my terrestrial plant mixes. As Anonymouse alluded, HD and Lowes usually stock bricks of decent quality Better-Gro Chilean Sphagnum for $5-6. Hydroponic or other higher-end gardening stores may stock the slightly more expensive NZ stuff, which usually has longer fiber lengths and less included sticks and debris than the Chilean.
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