There is no precise answer to the associated costs. It’ll be different for every circumstance. There are just too many variables and factors to consider.

If you have plenty of time, happen to already have good soil and climate, have all the necessary tools on hand, and are just lucky, don’t have to pay for electricity or water, and so on, the financial cost can be essentially 0 (or close to it).

The more you have to overcome your situation, the more you want to make the cultivation easier, the more you want to maximize yields, and so on – generally that’s going to incur more financial cost.

There could be upfront costs like installing automated watering systems, amending your soil if it’s not up to par, building raised beds, building fencing or installing edging. Plus, any tools you don’t already have, which might include shovels, snips, wire, a spade, and so on. Even if you’re growing on a balcony you might have to buy pots and potting soil, invest in some shade cloth, put down some saucers to protect your downstairs neighbors from getting dripped on. Those are just a small sample of potential upfront costs.

Ongoing / annual costs might include things like fertilizers, pesticides, compost/mulch, replacements for any of the upfront stuff that breaks, and even things like cost of water (which is hopefully negligible but not always).

So, if money is the only “associated cost” here, then it could basically be nothing, but it also wouldn’t be entirely unusual to spend a couple hundred dollars (USD and US costs, I can’t speak for the entire world) and some folks even spend thousands.