What is your "inexpensive" hobby that turned out to be expensive/ you gradually invested lots of money into?

It's all about learning to mcguiver shit. If you have some land/trees keep all the leaves, branches and yard debris, + some cardboard boxes. I fill like a foot or two of every big bed or container that way before I use soil. Cheap material for containers like using big plaster 55g drums cut in half or the top cut off can be found easily. I like to use galvanized roofing sheets with some framing for large beds.

Gardening is a great way to save money from sitting on your bank account.

The raised beds were only $200 for the wood.

I blended compost with my sandy native dirt for only another $200.

The cute fence around it was another $200 plus... Plus $100 for the new tablesaw blade because I needed it to make it.

The additional irrigation setup was only $80.

I get the fertilizer with my employee discount, only around $100 per year.

The front flower bed was only $400 to make it tiered with retaining blocks.

Then there the $300 per year for flowers etc that I just have to have.

Then there is my vegetable seed bill. That's relatively cheap, only around $200 per year.

Since I start my plants I from seeds i need a starting setup. That's $200 for the lights plus another $100 for the heater.

Potting soil and trays are another $75 per year.

Then there's the steady stream of tools etc that I break or wear out and need to be replaced. Another $200-400 per year.

And then there's the koi pond...

The rabbit hole opened for me too.
Even started with growing cacti with seeds I foraged from opuntia figs in Italy

Oh yep, thankfully I am limited by the small size of my garden. But in the past years I've spend a lot on it. In the first year I only realised it when I made my budget at the end of the summer. It was so many small purchases but ended up to a big sum !

So true! Even two diy raised beds ended up costing quite a bit. Lumber is not cheap. Neither was garden soil. Buying perennial plants costs a freaking fortune. I am going to try for seeds for next year. Plus some bulbs. For vegetables, I need to learn how to grow tomatoes from seed. Of course that requires grow lights and such.

I started with a couple gifted plants, some hand-me-down pots and a cheap bag of potting soil. Figured I'd "keep it simple" and it wouldn't be much more than that.

Now it's different potting mixes, mulch, fertilizers, antifungals, and that's not even counting the durable stuff I want now like plant stands and even a humidity tray. Oof.