Seems interesting that so many seem to think it is a glitch . I would class a glitch as something that happens once , maybe twice . When it is an ongoing occurance , I would look for a different explanation.
Seems logical to me that it is an attempt to draw interest to something ( At the low price) , people get the idea in their head for something they would not otherwise have done , (but now they're excited for it ) , In the hopes that people will then book at a higher price anyhow..
....VERY Sketchy !!!
Cheers