Why are you viewing them as mutually exclusive things? Drop Prime (aka Amazon Sunk Cost Fallacy), and just accept that your orders will take a few days longer with their Slow Spiteful Shipping. I don't think the the Walmart sunk cost program even affects the shipping time, which mostly ends up being quicker than Amazon's Spiteful Shipping. Same thing with Target and every other large vendor regardless of whether they're pushing a subscription gimmick or not. Hitting a minimum order amount is really not hard once you've got items you buy regularly from each place.