I'm currently filming in Norway with the guys from Turbulence, i'm running Avid xpress pro on a reasonable spec Dell latop and it hasn't let me down once in ten straight days of constant importing and editing.
Often you may suffer problems importing your footage if this is the case try using moviemaker, it will accept almost anything and is a very handy way of guaranteeing footage capture, save the footage at full DV quality and you should be able to imprt it into your chosen package.
As for the 'high' cost of Avid, a full retail version costs around £1300 but if you can prove student status you can, as i have, get it for just £185.