Home Improvement Business: Expansion Advice Request

Hello r/entrepreneur, experiencing success since opening home improvement business. (shower niche)The service costs $600aud. A technician goes to their house, completes service, takes 3-4 hours. Clients love it.Now, technically clients could assemble materials themselves from various hardware stores. (tiling, plumbing and general hardware shops to be specific).They’d also have to complete the service theirselves which is possible with video guidance if you’re even somewhat handy.Though the cost would be say $300. As materials can’t be bought individually, the quantity of each material they’d need to buy creates an excess for what they’d use it for.Each job costs us $25 in materials, as we use the excess on the next job. Nothing goes to waste.So - this is where I need your feedback.In order to reach the my whole country rather than within 20 miles; is creating a DIY box w/ instructional guides the way?Any and all wisdom is greatly appreciated. - Tom :) see hubwealthy.com/wealthy