bird in the hand
A benefit available now is more valuable than some possibly larger future benefit. For example, Bob thinks he might do better in a bigger firm, but his wife insists he should stay, saying a bird in the hand. This expression, which in full is A bird in the hand is worth two in the bush, was an ancient Greek proverb. It was well known in English by about 1400 and has been repeated so frequently that it is often shortened.