I have seen innuendos of a $11/day (could be old numbers) charge for "early return". I would not mind paying that at all

Perhaps, as you posit, the monthly rate is targeted less toward tourists as essentially mini leases. I don't begrudge them whatever policy they want to market, but it seems darn hard to figure it out and I have no confidence in their customer service if I make a call. Thanks for your comments.