I'm a noob on here, but have been in the industry for nearly twenty years, and have looked into the same thing. Here are my thoughts/suggestions:
- Consider joining AOPA and use their many resources (flight planning, training info., ownership, etc...) There is a ton of things you can learn from them. There are other organizations, too.
- General rule of thumb is if you will fly the aircraft about 100 hours per year you will come out about even to renting, more than that and you will be saving money/hour.
- Buy an aircraft with engine time remaining. i.e. you buy one with 1500 hours and put 500 hours on it training, it's resale value drops considerably because the next owner will have to do the overhaul right away.
- Buy an aircraft with the equipment you want. Upgrades never recoup their investment on resale. Let the previous owner take the hit.
- Consider a flight club or partnership as alternate means to reduce your costs. Again, lots of information from AOPA can be helpful.
- As a student pilot, you should be able to get a free 6 month subscription to Flight Training magazine, which will have other good info.
- Caring for your own plane (as far as regs allow) can be rewarding and educational. You can & should work closely with your A&P on the other stuff to get to know your aircraft inside and out.
- You know how well the airplane has been treated vs. how did the last renter treat it/report squawks, etc...
- It's a big investment and if the economy tanks you may be left holding the bag until it recovers.

Just some thoughts. There's probably a lot of other advice out there. Keep reading. Good Luck!