Buy once, cry once.

The cheap ones can end up warping or flexing and as a consequence you lose the seal.

Is this as a secondary storage or do you really want something to take on a weekend trip?

The Xikar branded ones have a sturdy, hard plastic shell.

But I get being frugal - if its for a weekend trip and you'll be in possession of the traveldor, you'll smoke 'em faster than the seal can probably leak. If you're flying or want to use it to store for a month or more, get a good one.