There are many proponents of noise cancelling headphones as a tool to help reduce jet lag symptoms. You don't have to listen to music to use them. They don't block out every single noise - you'll be able to hear announcements on board for example - but they do cancel a lot of the extra noise congestion, and this is touted as helping one relax and feel less lag at the end of the jetting around.
These headphones receive really favorable reviews and start in price at the $95 range.
There are a few merchants that sell these just under the $100 mark, even though others charge as much as double that.
These were the least expensive noise canceling headphones I found, starting at the $10 mark online.
These can be purchased between the $20 and $40 mark online.
Generally well rated, this set should set you back about $60 - $100.
Although often a pricier set of headphones, several stores online do sell these comfortably below the $100 mark.
Well reviewed, and well priced - these headphones range in price from $25 - $40 online.
Priced around the $40 mark online.