In agreement with goblue.
Peter/Predrag, continue renting skis and boots until you become an Intermediate. If you're still doing the wedge to get down "most beginner trails", you're certainly still a fresh beginner. You should not considering investing in any equipment (except a set of good ski clothing and accessories) until you can get down any-and-all Intermediate (blue square) trails by skidding. Even then you should not consider buying skis yet. At that point you should go to a reputable (that is, somebody recommended by an authority, or by consensus here) bootfitter and invest in a good pair of boots professionally-fitted to your unique feet. From that point on you might find that you're ready to learn how to carve. And at that point people will have a better answer for you in terms of buying skis.
Like I said, you can't go wrong with investing in high-performance winter clothing right now. Not only will a nice waterproof/breathable shell jacket/pants (Gore-tex or comparable competitors) + gloves (also waterproof/breathable) + goggles + high-performance underlayer (merino wool, structured polyester, etc.) + helmet all contribute to making you much more comfortable, it will also improve your winter outdoors athleticism, which may allow you to improve faster. Finally, much of this stuff is transferable to other activities, so it's multifunctional.
Edited by DtEW - 1/8/10 at 1:18pm