To access the travel corridor, a passenger from Hong Kong to Singapore must take a coronavirus test within 72 hours before departure at either one of the 19 government-accredited laboratories, or at one of the four community centres starting their long-term operations on November 15 and charging HK$240 (US$31) per test. No arrival test for Hong Kong passengers is needed at Singapore’s airport.
A traveller from the city state to Hong Kong would similarly need to take a test in Singapore during the three-day window ahead of the flight, costing between S$200-300. On arrival at Hong Kong airport, the passenger must undergo another PCR test at a designated zone for HK$490.
A passenger travelling between the two cities within three days would not need to take another test before the return flight. The minimum screening costs for a round-trip would therefore be HK$739 per person.
https://www.scmp.com/news/hong-kong/health-environment/article/3109315/hong-kong-singapore-travel-bubble-launch-november