Holleyweb offers tents, which can sleep one as in a bubble. That, however, to the $1000 stump up. Not exactly cheap, but I would already like to kip out there all. At the beach…

Inflatable bubble house can be easily installed in parties, parks, amusement centers, backyard, gardens. Cheap inflatable bubble lodge for outdoor camping and beach sight-seeing.

Sleeping in a bubble
Sleeping in a bubble
Sleeping in a bubble
(via Laughing Squid)