i've heard of frens who have been other brides' jie meis before, they received angpows from the couple, amount is usually above $30. It depends on what you expect them to do, if they help you to plan, find your wedding gown, emcee, torture your hubby at the door, etc then i think they deserve more cos quite a lot of effort on their part, giving up quite a few days of their time. and i think they will really appreciate food and drink during the day. e.g. if you expect them to arrive at your place at 7am, then better have breakfast ready.