Forum Moderators: LifeinAsia
The process you're talking about is a normal part of doing business for most b2b firms - it's called 'qualifying a lead' (searching for these terms will get you a fair amount of info).
You want to assess how likely it is that, if you put time and effort into the sales process, the sale will actually go ahead.
Some of the things you might want to assess are: does the company understand the value proposition for what you're selling, is the budget in place, when is the project going to go ahead, what happens if it does/doesn't go ahead, and who makes the decisions.
Of course you need to know who you're dealing with; it's not at all unreasonable for you to ask (politely) for further details. Tell them it's so you can prepare a personalised quote for them (which should be true).
All this is apart from finding out what the project actually is, of course.
I wouldn't be so worried about competitor enquiries - what are they going to find out from a sales proposal that you would want to keep confidential? If they're a competitor that you really compete with regularly - e.g. you're a local web design firm and they're another one in the same area - then they probably already know roughly what your pricing is like. If not then they're not very on-the-ball and maybe you don't need to worry too much about them! ;)
hth,
a.