I'm in the market for an all terrain pallete jack, and I've come across a decent used offer. The seller sais it's been used twice, but didn't suit their needs, so the thing's been sitting in a barn for 6 years. Is this a problem? What should I be wary of?

Any other pointers to buying used pallete jacks? I'm a complete newbie to all this, so any feedback would be much appreciated!