I've got the most inexpensive suggestion yet. Don't snap the lid down, just set it on top. I've done this for the last 18 batches or so, and not a single problem yet. No more fooling with the stupid airlock either, just not needed at all.
I know, kinda radical, but give it some consideration. After all, in all the history of human brewing, air locks and sealed fermenters are the latecomers to the party.