This joins "taxis are dirt cheap is Dubai" as an enduring travel myth.

Well placed 5-stars in Jakarta can offer value compared to Hong Kong, London etc, but can also be painfully expensive for self-funding visits, especially after tax and service is added in. Lower rates are at weekends.

As it seems the OP might be in Indonesia for only one night, I'd suggest one of the hotels in or around the airport. The ex-Sheraton, now Bandara International is pricey but on-airport (though still needs a shuttle): there are Ibis hotels and some smarter offers close to CGK. In the city value is in second-tier chains such as the Holiday Inns and Doubletree. For hotels next to the city centre rail link at BNI Sudirman station, look to the Holiday Inn Express Thamrin or the All Seasons. They should give you change from £40, and are within a short walk of the Kempinski and the swanky malls.

PS the airport to city rail link I refer to above is recommended over taxis as it gives (more) dependable timings for the city-airport trip. Trains run every half hour and take something over 45 minutes though there's a measure of faff getting to the airport station. Tickets are easy, using credit card. A taxis usually takes about one hour, but that can easily run to ninety minutes or more: my record is four hours.

For the single passenger the rail ticket represents half the taxi fare. OK, that's £5 instead of £10, but it's till a saving .