I'll try to give you a few insights. (long post, be aware!)
(I will try to make it clear and simple, however you have to forgive me for any misleading translations since i am french and scientifics words may be from time to time hard to explain in an other langage)
First of all it depends of what SHE thinks rather than what people think here. Most of us, Whatboyswant members, would say that almost any tits are great. In the worst case you will just not hear those who don't like a certain type of body (in this case her boobs)... With the exception of a few smartass. So your population is NOT representing what you need to know.
However, it would be good, if your wife was into it, to post pics of her, with her knowledge, and to show her all the " woah nice boobs girl " from all of us. This would help her a great time to get her self-esteem way higher than what it is actually.
This leads me to the most important point : her self-esteem. Unlikely most women, she USED to have very nice boobs (i must say) and they have gotten worse.

In her mind, she is telling herself that she still can have these nice boobs (like any women who have once had great breasts and had a baby or two... You know the results..). The comparison (with mothers) is even better since they all go through that but a few exceptions (the exceptions are those who still have great breasts after giving birth). In both case, she is comparing herself to these women and want to be like them. You can add the fact that she has (and had) a very great body (way higher than average) and she's got addicted to it, by the way that people stare at her, by the way she used to wear sexy clothes (say bikinis or bras in example) and more.
I could give you a second idea to get it fixed up and its called exercice and work out. If she works on her higher body, with a good trainer, she would be able to manage to get more muscles in her breast, helping her to have a firm breast without losing fat (and possibly slightly bigger without looking like these women who are way more stronger than i am!).
One thing you also need to know is what size she is willing to get. If she wants the same exact size she used to have, with the same tits, then she does miss (like i pretended) what she used to have, and surgery would be a fast way, more expensive but still good way to fit it up (but not the only way to fix it). However if she wants way bigger (not a little bigger but WAY MORE bigger) then i would suggest her to go see a professional (ie a psychologist) because there might be a whole lot more problems behind that, and the "boob job" would be the compromise she is doing (unconsciously wise) to wrongly fix it up. What i mean if you did not understand is that in the future you could see some problems coming up that would be related to that. This is not a sure thing though and the professional could tell you.
Telling her sweet things, such as how gorgeous she is, is a good thing, however the human usually get used to something too commun, not matter what it is, and even more when it comes from the same source (in that case you). I am in no way telling you to stop, not at all, however you just can not expect it to work properly since you two have been together for at least 5 years (since you had pictures of her at 18 and now she is 23, correct me if i am wrong). If it was coming from us (whatboyswants members) then like i said, it COULD work, however i wish you good luck in handling the fact that you already have shown pictures of her :P
Nonetheless this is not an easy decision to take. I would say that the specialist doing the breast surgery would give your wife (and i hope you) a paper with a bunch of questions to answer, to ensure that you two are taking the best decision. However these days you can not even trust doctors (especially in a capitalist society).
Finally i would give you a small trick that i use in a lot of different situations (almost all). Its all about your priorities. In that case, its a mathematical calculation between (not exclusively) :
-money
-self-esteem (her look)
-time (how fast she wants it done)
Give them numbers if you want, the way you want, or just think about it. Say a poor person without any jobs would rate "money" at a very high level in priority. However you may have enough money to rate it lower while your time is pretty short (too short to do exercice by example)
I wish you two good luck and i hope it helps

I'll try to keep a look at this post from time to time to help again if necessary
* This post has been modified
: 19 years ago