You can decide whether to buy 奶泵 after you confirmed you can 喂人奶. I heard from many friends that they are not able to 喂人奶 at all. Don't raise money initially, just borrow from hospital (if you are in private hospital).
My baby is 8 months now and still having and still half time 喂人奶 (morning and night 埋身餵, one time with bottle). The first few days you may not able to 喂人奶. I will suggest you to borrow 奶泵 from hospital to pump in the first few days so as to speed up the process and relax the pressure inside