Gardening is inexpensive compared to keyboards. For a hundred bucks that's a ton of gardening stuff, even new. Or you can rummage through estate sales and grab bags of fertilizer, seed, pots, trowels, miracle grow, and whatever else for close to nothing. Literally. I grabbed a brand new bottle of $10 poison ivy killer for $0.50. Mulch is inexpensive at $3 a bag and that only needs to be added onto every year. Throw in some hardy plants and really all you have to do is trim every once and awhile.
The biggest pain is so damned aphids and the rose bush. Those bastards just don't give up.