Jakarta has an unusual reputation compared to most big cities in Southeast Asia. Many people recommend skipping it altogether, but it’s the main hub for reaching almost anywhere else in Indonesia (except Bali) so many people stop here anyway. Jakarta is enormous, crowded, sprawling, and always hot and humid. On a positive note, it has excellent shopping and nightlife, and things tend to be pretty cheap.
There aren’t many hostels so it’s fortunate that hotel prices tend to be quite low for what you get. In fact, Jakarta isn’t a bad place for a little splurge, since backpackers in pairs can often score a great deal at a 3-star hotel for only a bit more than a hostel dorm.
As long as you like Indonesian food (as so many do) then you can eat very affordably in Jakarta. There are also plenty of fast food chains and international options, but the best deals are always on the local stuff. Beer is quite cheap as well, as long you enjoy the ubiquitous Bintang lager.