My first racket I found at KMart for $25 and I absolutely loved that thing until it broke in my luggage. I went from beginner all the way to captain of my high school team with it--and got 2nd place in mixed doubles at the year-end tournament, so don't think just because your racket was inexpensive that it's crap. As a beginner, your issues are likely not with the racket, but with yourself.
In college, because my beloved racket broke, I was forced to buy a new racket. I chose a Prince Warrior TT OS because my favorite player at the time was Rafter, not because it was a "good" racket. It turned out to be a good racket for me, but I also found these forums and TW, so I went on a bit of a demo odyssey in college, searching, as many do, for a holy grail. I demoed probably 30 rackets and bought and sold 5-10 more. While demoing, I found that often I'd hit amazing with a new racket for about a set and then all the things I normally had trouble with, I had trouble with again after that first set. So, again, even as a 4.5, I felt the racket is only a minor piece of the equation.
Exception:
I also taught my college roommate tennis. He was about 6'2 and probably 275lbs and a drummer. His forearms were the size of my legs. He went to the pro shop and told them he was a beginner and they sold him some ridiculously light 115 sq in. 28" long rocket launcher of a racket and he literally hit every third ball over the fence. He demoed a few rackets with me, but still launched balls until I suggested he try the lowest powered racket I could think of--the PS85. All of a sudden, he became a decent player. His problem was that he was so dang strong that he needed a low powered racket to tame his strength. This is just about the only condition I can think of where the racket made a big difference.
