In all honesty, in Singapore, it is a lot easier to crack into the market as compared to overseas such as Australia, UK, US and etc...
My observation and experiences tell me that the concept of professional photography has yet being accepted widely nor practice enough here because, there isn't enough many of professional that is willing to spend time "educating" their client...
$$$ get you started, yes, it is darn right but you really don't need a lot of it to begin with. If I could quantify my initial outlay when I first started my business in Singapore were merely $10k. Of course, it will be more or less depending on what you want to do and what market you are targeting.
Once you make money, you simply need to reinvest those money in business essential.
But it still takes a lot of good business management and cash flow management to ensure the success of a business. But of all that, you must have a product that sells.
Unfortunately, the images created is merely a product in photography business. If you market your product at the right price (right price doesn't have to be "give-away" price) to the right people, you are in for a long run.
The crucial thing is knowing where and when to pull the plug on many business decision.
Gear upgrade should be last in your list. Knowledge and business upgrade should be priority... both artistically and of course the business knowledge.
I hope I make some sense... late night, lack of sleep...