Bubbles are great in caches where there is routine owner maintenance. Lacking the knowledge of whether that may happen they probably are not great swag.

Cache Maine and I came across a two caches recently which had gone through the winter with bubbles inside and no owner maintenance after the thaw. What a mess! Fortunately we had supplies, could clean them out and get them all set to go again.

Recently took a 10 year old caching - her greatest find and "All for a Dollar" was a real Gold dollar.