Low zoom tile download single use

Hi, My objective is to get tiles for the whole world, at zoom levels 0-9, one time, for offline use. I'm trying to figure out the best way to do this.

I know the "proper" method is to download OSM data and then run a tile server. However, this seems overly complicated considering the application. I think I'd have to download the entire (60+GB?) OSM data set, despite having no need for most of the data that would only be valuable at higher zoom levels, and I would have to figure out how to set up style sheets, mapnik, etc, all to just run once.

I know there are ways to download tiles directly (eg JTileDownloader). I also know there is a tile usage policy which says not to download large amounts of tile data. http://wiki.openstreetmap.org/wiki/Tile_usage_policy. At what point is downloading considered excessive, eg I'd be doing a few hundred thousand tiles, once per year (or even less frequent), not multi-million tiles on a regular basis. And the tiles are already rendered/cached, I would not need them regenerated. So I think my application is not putting a major load on the servers, but perhaps someone could clarify that? (Or should I just try to contact a system administrator directly to make this request?)

If there are other options, please let me know. I know various resources say that Mapquest tiles can be bulk downloaded, but I'm not totally sure if terms have recently changed.

Thanks for your feedback!