My friend is organizing a birthday party for 30 people. she has in mind something along the lines of a buffet with assorted food, enough to constitute "dinner" for her guests. she's not sure if she should contact restaurants, or if she should contact a caterer or an upscale grocery. cost is something of a concern - if she could keep it to $600 or less, this would be ideal. She's flexible re: cuisine - was thinking Asian (e.g., thai), but this is not necessary. Location will be a large loft apartment (so there will be a kitchen, if that helps). this would be for a saturday night in late August. Ideas?