If you want to save money, and find out a lot about your body, you may want to consider using Fertility Awareness Method, or FAM. You can find out a lot about it on the Internet and from the book Taking Charge of Your Fertility by Toni Weschler. I used this method for 4 years as BC and then was able to use it to time intercourse and got pregnant our second try.
The method involves charting your waking termperature and observing other fertility signs such as cervical placement, cervical mucous, and your own personal fertility signals. You chart these signs and observe the patterns they reveal. For example, you may notice an increase in cervical mucous with an eggwhite-like quality before you ovulate, then a dip in waking temperature followed by a significant rise. This would mean you ovulated.
I eventually got to the point where I didn't tracks temps but only cervical mucous, but I'm also very regular and we used condoms as back up if there was any doubt. The true way to use FAM for BC is to chart religiously and abstain starting at the first signs of fertility and for 3 days after you ovulate.
The other advantage to FAM is you can find out other things about your reproductive health. Because you're always aware of what's going on you can identify cervical changes that may be a signal of illness, and sometimes hormonal or thyroid imbalances. I have a friend trying to get pregnant and she's identified a progesterone deficiency based on the low temps she sees after she ovulates.
Obviously, I'm a big proponent! Sorry this gotten so long. I hope you find a method that works for you. And hats off to you for looking into alternatives to hormone BC!