unity – How can I develop and publish a game when I do not have money to buy a new computer?

I would like to complete and publish a game made with Unity, but since the cost of a new computer represents a significant part of my annual income, I do not have enough money to buy one.

My final goal is to publish the game on iOS.

Apart from generating more income in advance, what are my options?

Moderators' notes: We have asked this canonical question, so we are looking for non-specific options (for example, avoid pointing to specific regions or suggest buying specific models, etc.); We would like to help future visitors who come from all over the world, during the next years.