Now that Amazon's (AMZN -0.33%) online grocery store has gone live in the Los Angeles area, more details have emerged about the costs associated with becoming an Amazon Prime Fresh member. Once the 90-day trial period expires, your Prime membership will be upgraded to a $299-a-year Prime Fresh membership. Fool contributor Steve Heller wonders if the high membership fee is an ingenious move for Amazon to drive new spending, or if the price of entry is too high to have mass appeal. Be sure to check out the video below to get the full story.