Another great question! It really depends on the size of the garden and what is involved in the design. Perfect lawns are by far the most expensive aspect to most landscape/garden designs. A garden reverting to weeds and invasive plants, with overgrown shrubs and poison ivy, is the most expensive one time project, second to large scale tree working.
Cutting down or pruning large trees costs a lot because it takes large scale equipment, crews of arborists, sometimes a police detail in parts of cities, and it is a high liability industry so insurance costs for tree service companies is the highest in the industry.
Any company that uses large equipment for large projects or sometimes just to make the dough on smaller size projects ( because the business wanted the toy or thought it would bring in higher paying projects), are also going to have very high insurance costs.
In staying a one woman operation, with my life in my own hands when taking on any project I advise is safe enough to survive, I stay very low budget in my overhead costs. Being a seasonal business and having employees means also paying for unemployment, workman’s comp, liability, health insurance, and I would need to have more trucks, so more insurance on vehicles and gas, etc. The bills pile up. Lets not forget paying employees, which is why a lot of landscape companies try to find cheap labor, like all industries in this modern era, costs are high. Owning a small business can get very expensive. Even when doing everything by yourself. I have yet to see which is most successful path. My choice feels the least stressful. The risk and control only fall on myself and not others I cannot be accountable for. I am able to offer a competitive price to most in the industry, with more knowledge than most and with the efficiency of often a team of unenthused poorly paid seasonal help, or the team sent to milk the hours for the company to make enough money to survive. Occasionally more efficient than a team of men, but only if they are unfocused. The work and desire to achieve falls in my lap. I deliver what I sell and I hold myself accountable to the whole process, from sales woman, to designer, to laborer, to accountant, to business owner.
Always discuss with your Landscape or Gardener Professional about annual costs of maintenance for what they have proposed as a design or what you currently have as a design. Talk about your budget and how they can help you stay within budget. Sometimes big money on the right mulch in the spring spent on a garden means less maintenance visits through the summer to weed.
As I have mentioned in all my articles, the relationships you are building with your professional are always going to be specific to your garden’s needs and your needs as a homeowner and client. Make your needs known to deduce if they are the right professional to grow with you and your garden over the seasons to come!