First, $69.99 after discount is way too much to pay. You can find them anywhere else for that price standard.

If you are still paying $70 after discount just order one online or go to another store.

If you are doing Blazers you really do not need the right helical. A lot of people use offset and it works well. Even Bohning says that you can use either and their Blazer jig uses offset, not helical.