Skylimo to Guangzhou cost from HKIA?

Can't seem to locate rates for skylimo from HKIA to Guangzhou. What is the going rate? I have 4 people in my group. Does Skylimo take you door to door from HKIA without having to transfer at the border? From my understanding, you have to get off the bus, take all luggage with you, wait in line to cross the border if you take the bus service. Is that correct?