I think there are good points on both sides of which visa to go for!
The main thing is to think if you are willing to move to the UK and have a wedding without your family and friends from back home. If you are okay with this then a fiance visa is a good way to go. Does cost really come into it? The visa and wedding is a costly venture regardless of how it is processed (from what I have read)..
From your boyfriends point it is better to get married in the UK as that 6 month period will give a better indication of how your lives will pan out. I am sure those 6 months will be bliss for you as the honeymoon period as they say is still ongoing at that point. But, at least you get to see your future husbands habits up close. I mean, his day to day habits. The way he gets ready for work, the way he cooks.. etc.. And if for some reason at that point you both have a change of heart it is easier to deal with than when those vows have been made..
My own personal thoughts with my Mahal on this matter is that it will allow her to get to know the UK a lot better and make some friends before making the big commitment. I think if she can get through those 6 months and still marry me. Then our marriage would be stronger and the odds would be with us instead of against us. But then we both understand that at times we will have our problems and commitment is not just about the good times!!
Whatever route you take.. Good luck
