I’ve just added them, generally sample set packs would be for whole other category of sample/sampling packs but because I haven’t seen them in other posts yet I thought it’s worth including. As for Pokémon Web, like you said, the pack is transparent and holds no actual art so I left it out.
I also saw an old post that has excellent coverage of sampling packs and dollar tree packs so I’ll share it here as well:
Sample Packs Dollar Guide Gallery