Forgive me if this has already been said. I've been reading these forums for about 2 hours now this morning and my attention span is starting to suffer.
When my therapist was trying to figure out where I fit on the transgender scale, she actually mentioned that there are a decent amount of people that choose HRT with no transition. If that's what you want, then it's right, whether anybody else agrees or not.
On the other hand, I've seen several threads on this site showing the before and after of HRT and for the MtF direction (the one I remember because it relates to me), it really is not just breast growth and skin texture. There are a lot of other visible changes that may be more than what you had in mind. Make sure you do your research before you commit.