Ceramic tiles are the best option, since they are not as expensive as porcelain. Both materials are sturdy and reliable and, if properly installed, will last for decades. If you decide you want to re-tile your shower, that's when your costs may increase. Once again, if you choose to do it yourself, you will save money.
What is the cheapest way to redo a shower? The economical choice for remodeling the shower will be between acrylic and fiberglass. There are prefabricated acrylic panels that can be quickly and easily applied to the walls of the shower. Retaining and refurbishing existing materials is always the best option to save money. But if you have to change materials, inexpensive alternatives can often look incredibly similar to the real thing.