Our freezer side of unit will start thawing out, and freezing again. The ice begins to thaw, and then it freezes all together. We are now having to put ice bucket under hot water once a week to get all ice out, as it no longer will dispense, because it is 1 solid mass. There are times when we open up freezer and you can see condensation inside. I constantly check that the kids haven't left the door partially open. We had a repair man look at it, he said he couldnt tell us that was the problem, but said that is what he would fix 1st. His charge to replace was $300+. The cost on this site is $134. Should I take his advice, or try something else?

If so, how easy would it be for me to replace it? I am NOT HANDY at all, but would like to save some $$.

Thanks in advance for any and all advice.