It depends on the size of the golf balls. If they are regulation golf balls then typically around 500 would fit.
However if you have larger golf balls then more would fit. For example if you have beach balls-sized golf balls then probably about 1000 would fit in a 747.
Are 1000 Golf Balls Enough?
That really depends on how much you love golf and how often you play.
If you are a casual golfer who only plays a few times a year then 1000 golf balls may last you several years.
On the other hand if you are an avid golfer who plays several rounds per week then 1000 golf balls may only last you a month or two.
In general it is probably best to have at least a couple of thousand golf balls on hand so that you never run out.
Should I Get More Than 1000 Balls?
If you are an avid golfer then you may want to get more than 1000 golf balls. This way you will always have plenty on hand and you will never have to worry about running out.
Plus if you have extras you can always give them to your friends or family members who also enjoy playing golf.