I got a pound puppy years ago for like $60/ spade and microchipped. Vet costs us $37/ month and $136/year in flea and heart worm meds. That sounds expensive but she can go to the vet visit for free the whole year. All shots are paid and she gets 2 full exams a year. There are cheaper options but she's old now. We use to only take her 1x a year for shots and we didn't pay the $37/month. Before we moved to FL we were able to get away with cheaper flea and heartworm medication. We feed her cheap food which is $23/ every 2 months. Sometimes we make her home made food. If we did 18 week training it would cost us $320. Also nail clipping 4-6x a year is $10 each time. So if you have about $75/month extra. I would say get a pound puppy.

There's also low income clinics that offer cheaper services. Including training.