Yes, it is. Of course, there will be an initial investment to purchase the kit plus additional expenses to maintain it. You’ll have to spend on electricity, generator (if preferred), pH and electrical conductivity testing tools, nutrient solution and new seeds or pods.
In the long run, you’ll realise that it is more time-saving compared to soil planting. Once you start harvesting, you can save money on groceries and forget about dealing with off-season produce prices.
Also, there are ways how you can make it more cost-effective. One is to pick a garden kit that’s value for money. Start small and go for low-cost models first. If you want to continue gardening indoors, you can also invest in a recycling system so you can disinfect, reuse and save water.