Howdy Michael,
Welcome to Trad Archery. Here's my two cents worth...
Don't "over bow" yourself. If you are comfy in that 45-50 lbs range, stay there. If you are drawing a true 30" and have been shooting a bow that's 45lbs@28", you're probably actually drawing around 51lbs. You'll shoot better and practice better with a bow you are comfortable with.
Next, peruse the Classifieds here for a used bow. There are lots available, and you will be able to pick up a top end bow for considerably less than new. I personally recommend a Chek Mate TD Hunter II. Should be able to get a good used one for $300-$350...
Lastly, practice, practice, practice. That's the only was to get good...