First random result in Google with key word "compare cost of hong kong to bvi company":
ABSCPA - Hong Kong Limited Company Formation : Hong Kong Company Comparison with BVI Company | Incorporation Requirement (Compare) | Purpose and Benefit (Compare) | Cost in incorporation, Maintenance and Cancellation (Compare)
As for prices, you have to shop around. I found the best "agents" are the smaller more local companies. They are cheaper, and you have a direct contact by phone/email. Prices vary a lot, really. For the setup it might not matter a lot if you pay a few thousand HK$ more, but if you pay a high price every year you'll just regret that you didn't choose a more humble agent at the beginning (been there, done that).
Maybe the $2k/year figure from the other thread was for somebody who does everything in-house by himself and is a HK resident, or maybe they just never registered a company before. He might not need a secretary, accountant, auditor and somebody to file the tax. Normally that's arranged or done by your public accountant who sets up the company for you and it costs money. Well, that's basically the money the earn. They don't help you setting up companies for no reason.
Almost any HK public accountant should be able to provide what you need, even if they don't have a fancy web site.