Price differences in water filters

[SHRED]

They are all over the map!

I am tried of hauling around bottled water and I am looking for a solution.
My first idea was a two stage filter like these but the price discrepancies are confusing.

$149.99

$59.99

I am also considering the cheap exterior blue Camco inline filter and something like this:

BRITA

Or better yet:

TRAVEL BERKEY

Thanks for any suggestions.

[midnightsadie]

$25. inline filter with a charcoal filter works.