A DIY greenhouse can cost as little as a few hundred dollars or as much as a few thousand dollars, depending on the size and features. There are many factors to consider when building a greenhouse, such as the size of the structure, the type of materials used, and the features included. Some people choose to build their own greenhouse using recycled materials, while others may choose to purchase a kit or hire a professional builder. The average cost for hiring a professional builder to construct a greenhouse is around $1,500 - $2,000. However, this price can vary significantly depending on the size and complexity of the project.

There is no one-size-fits-all answer to this question, as the cost of building a greenhouse will vary depending on factors such as size, materials, and location. However, a basic greenhouse can be built for around $1,000-$2,000. If you're looking for a more elaborate or custom-designed greenhouse, the cost will be higher. For instance, a glass greenhouse can cost anywhere from $5,000-$25,000 or more to build.