Hi, i would like to know the On-arrival visa procedures for Hong Kong

I am currently working in UAE & I am planning to make a 3 days visit to my fiance in Hong-Kong with my mom. We both will be flying from India. So i would like to know how much cash (US / Hong Kong Dollars) should i hold to get an on-arrival visa and i would be grateful if you can detail me the other legal requirements for our visit.

Best regards.

Rebin Campbell