The price alone is pretty meaningless; it's what you get for that money that matters - that's called Value (or "bang per buck").

For a simple modem, $350 represents very poor value indeed;

For an advanced, powerful device (much more than just a modem) like the Cermetek CH2168 or these Multitech units, then $350 may represent good value.

Similarly-powerful devices (embedded Linux, etc) - at a similar price point - are also available here: http://www.owasys.com

So, as noted here, Erik needs to clarify his requirement.

If an advanced, powerful device (much more than just a modem) like the Cermetek CH2168 or these Multitech units is really what he wants then I have, indeed, misunderstood the requirement!