Hot Arizona Summers - need AC

My name is Gail, I’m a widow and live in my own home. My home currently has 2 wall units to cool off my home for the summers. I have the opportunity to get an actual air conditioning unit in my home for 6500.00 but I have no means to pay that much money. The summers are miserably hot and I’m hoping people can help me to reach my goal to get an AC unit before the hot summer months get here. If you can help me at all I would greatly appreciate it!