Since a lot of trans women started their transitions well into adulthood, male pattern baldness is a curse that many, if not most, of us have to address. Some catch it early enough that it's not a problem, some resort to transplants, and the rest of us wear wigs.
Wigs can range from el-cheapo Halloween wigs all the way up to the sky's the limit. You may eventually want to have several wigs, including inexpensive ones for daily use and better quality ones for dressing up. If you are full-time, you will want at least two, so you have one to wear while the other is being washed and dried.
For $150, you can get a decent-quality wig that is presentable in public. You might be able to find cheaper ones that are acceptable, and you can certainly find wigs that are much more expensive.