SINGAPORE EXPATS FORUM
Singapore Expat Forum and Message Board for Expats in Singapore & Expatriates Relocating to Singapore

Well, one way could be just to check how much it actually costs per person for typical weddings at the place you've been invited to. While I have my own "estimate" to how much I give each time, if you want to be more exact, simply give the venue operator a call, ask them how much it costs per table ...