Developing With Emulator Only

The emulator is slow and takes a long time to start. (but you only need to start it once in awhile)

You'll want to put the SDK in a folder with no spaces in the name and make the emulated devices contain no spaces in the names.

Also depends on what you want to develop. Connecting to the internet can be tricky but doable. I dont know what issues are involved with stuff like mock locations and Google apps.

Some hardware things will be untestable (for example: bluetooth, NFC)

 

doing an app would be doable, but for a game .. the emulator won't do
cause it's a lot slower than an actual phone

and again, when the emulator is running , don't close it unless you are done programming for the day

having one phone as a test subject would be good, you can improve compatibility using the emulator later on

 

The emulator is not recommended for testing your apps. Google's answer, so would say get a android phone if you can.