Hong Kong is well comparable to Cities as Paris or London. But you can get by quite cheap. How? It will be explained in this short "Cheap-Guide to Hong Kong".
Place to Stay:
Rather unusual but absolutely possible is a homestay at a guest familiy. For about 200HKD a day you will get a single room, breakfast and dinner inclusive. Most Families who offer homestays however are from the mainland China and speak Mandarin. Also Chinese manner are applicable. For those who have never been to China before I recommend a book such as the culture shock series.
Transportation:
Public transportation in Hong Kong are, depending on there speed and velocity, different in price. The absolutetly cheapest option is the tram. People of Hong Kong call it "ding, ding". One ride costs only 2HKD, but it is terribly slow and always crowded. A ride from North Point to Central takes about 35 minutes.
There are of course Buses, one ride costs about 5-7HKD for the same distance. Although at the rush hour you will get stuck in traffic jam. Both the tram and the MTR, Mass Transport Railway, have there own lanes.
To travel between Central, Wan-Chai, Tsim-Sa-Tsui, Hung Hom and North Point you can use the old Star Ferry. One ride on the upper deck costs 2.2HKD, on the lower deck 1.8HKD. A ride to cross Hong Kong harbour takes generally 10 minutes, sometimes the lower deck is unavailable during cleaning of the piers.
The MTR is the fastest public transportation to go anywhere. A short ride costs about 4-5HKD, but can be 8-10HKD or more for longer distances and between Victoria and Kowloon.
Then there are taxis. The Hong Kong taxis are easy to recognise by there red color. For short distances of about 10 minutes you will be charged 20-30HKD.
Meals:
A set menu in one of the most common fast food chains costs in average 45HKD. This includes restaurants such as Mac Donalds and Burger Kings for about 35HKD. Ajisen Ramen, Cafe de Coral, Yoshinoya, Maxim's and Fair-Wood for about 45-50HKD. Every other small restaurant is 50-60HKD for a meal.
Far more healthier are fruits from one of the market streets. 1 apple, 1 orange, and 3 bananas cost 7HKD, more or less. A bowl of "Douh fah fai", soft bean curd and yellow sugar, costs 5HKD. A cup "Douh jeuhng", soy bean milk, about 4HKD.