You might consider giving Garmin some money, then. They have a product with offline maps which apparently lets you buy map data and indeed basic functionality piecemeal. It's a dollar right now, but it's supposed to remain cheap. I guess they are or were also offering deals on content. Linked article complains about spending a hundred bucks, but if that were lifetime that would be well worth it. The big problem with buying a Garmin GPS is that the hardware pretty well sucks unless you spend a lot, and your updates are tied to the device so you could get into a situation where you're motivated to give them money to repair a device that was kind of lame (hardware-wise) when you bought it. But if I can take their app to a new phone when I upgrade, then I can let that unit go to a friend and just use my phone, which has a much nicer screen overall. In particular, text input on my Garmin is horrible. I forget what model it is ATM or I'd include that info. Suffice to say it was a cheap refurb.