Your country may have a free wheelchair organization that will provide the wheelchair free of charge, or at low cost. You can sometimes find a free wheelchair by contacting your local charity or church. They take donations of money and free wheelchairs, fix the free wheelchairs up to the best possible quality, and then distribute them free of charge or at a very low cost.
For those who are unable to contribute money or donate free wheelchairs, you may volunteer your time at such an organization to earn credit towards receiving a wheelchair for free.