well, i can see that massive amount has been put into rent..
if you're tight on cash, you can always rent a single room first, which is about S$400/month, plus deposit, should not be more than S$2000
S$4000/month is a whole unit, and seriously speaking, that's high rental, you can get $2500-$3000/month kind of rental in the eastern Singapore near the airport. Of course, it's not a condominium, it's a HDB flat which 80% of Singaporeans live in.
HDB flats look like this, and this is Pasir Ris, which is 10minutes from the airport by taxi