Cultus is a good car, but it lacks the looks of Swift, Engine power and features.
Resale wise, Cultus wins hands down and registration wise as well. Fuel economy is almost the same of both cars, i get 14.5/15kmpl in city without AC, light foot on Swift.
In the spare parts and stuff, Cultus again. Genuine oil filter for swift costs 950, and the other Suzukis including Swift and Liana can use the cheaper one, only 150 rupees but the 950 one is recommended for Swift and Liana. Expensive ehh?
Wish you the best of luck, buying a car is indeed a tough situation:)