When I delivered my son, I had 2 midwives there and their assistant. The one midwife (not my primary) was the best!! She was like my doula through the whole thing. She made me feel like I could go all natural and really reassured me through everything. She will most likely deliver me this time around as my main midwife may be away when I go into labor. Also my mom was there and she was a BIG help! Just having anyone, like a close friend is good enough I think. As long as they coach you along and encourage you and help you relax, you are good to go. My hubby did great for a first time around and even helped me as well.
I did not use a doula but my MIL was there during the delivery of my second daughter. She is not a trained doula but she COULD be one. She's that good.
If you can't afford a doula, try to see if there's a friend or relative that could offer you the support you're needing.