I've done SIN F1 GP for the last two years, and while I don't mind the place I'm not planning to go this year. More than happy to share my hard learned advice from these two trips.
Firstly, either grandstand backing onto the Padang (suprisingly Padang A or B, or Connaught) are your best bang for buck. Seats are around AUD500 for the full event. Those stands give you multiple entry/exit options, and quick access to the Esplanade if any of the post-race events are your thing.
These stands also give you easy access to great food on track. Because of the number of vendors they have on the Padang, lines move very fast and prices are comparable with what you'd pay elsewhere in country.
Avoid the Bay Grandstand. While nice for the price conscious, the views aren't particularly exciting and its a real prick of a stand to exit the venue from each night.
If you can get accommodation for 2k you're doing well (I'd love to know how frankly), on average you'd be looking 3k for that period in a decent 3-4 star property around that time either on Sentosa or on/off Orchard. Clarke Quay is generally 4k to astronomical.
Another word of warning from hard learned experience, most SIN hotels also cheat and quote prices in the booking engine exclusive of taxes and charges.
If you're like me and not up for the high grade digs for the event, there are 2-3 backpackers in Singapore that I'm more than happy to give glowing recommendations for. They have top-flight security, quiet, well behaved, and on the doorstep of all services (inc. one which is literally opposite an MRT station). On the plus side, this'll give you some more coin to spend on tickets for the race and shopping.
Feel free if anyone wants to pick my brains some more.