It is actually a common misconception that bfing causes saggy boobs. Actually bfing doesn't have any effect on this at all - other than to give you bigger boobs while you are lactating. Age will do that to boobs all on it's own, but pg gives it a pretty good kick start. Women who have babies but never bf are no better off than mums who have bfed.

So the answer to your question is no, it doesn't matter at all.

ETA. You should see my horrible boobs, but I think of it as a badge of honour. They have done their job nourishing my two boys and now are showing that my body has created life. So I'll never be a lap dancer - oh well, I'll get over the disappointment!!