Hong Kong is the pearl of the south. It's a fully integrated match of China and Europe, with all the best features of both. This is a modern, cosmopolitan city with a lot to see in a small space though you can literally explore it on a shoestring budget, without wearing out your shoes. Travel insurance and economy trips are easy to find. You can do all your business and bookings online,
For tourists, Hong Kong has always been and remains a great place to go. It's quite cheap, by world standards. Anyone who's ever seen the South China Sea coast at its best will appreciate the comfort, the modern luxuries and the deep Chinese character.
Like the rest of China, the only real risk to your budget is the desire to buy all the beautiful things you can find. Hong Kong is one of the major distributors of the fabulous Chinese art, cultural items and furniture around the world, and Hong Kong shopping for a bargain is positively addictive.
The trick to a cheap trip there is to pay all your travel insurance, accommodation and fares front, and make sure you've got enough in your budget to shop carefree. You can buy everything else when you come back, anyway.