$250 will get you into almost any Jakarta hotel. Personally, I'm a huge fan of the JW Marriott, but location isn't as central as eg. the Hyatt.

For flights, Air Asia is actually probably your best bet overall for flights in Indonesia, although their network outside Java is limited. They're run to Western standards, do not cancel flights out of the blue (although like any LCC you will get delays), are very cheap when booked in advance, and above all, you can easily book their flights online, which at last check none of the other Indo carriers, even Garuda, let you do.