Agreed with everyone else here- the hardness of your water is likely fine as long as you aren't trying to breed. If the hardness is so high that it would be a problem for the fish you want, then stuff like driftwood or peat moss won't make much of a difference.
I tried with my wife's 29 gallon when she was living with her parents way up north in the state with well water. GH was in the 20 degree range, KH was around 10- african cichlid water. She wanted glass catfish but they're not tolerant of very hard water. Tried driftwood and peat moss and it did nothing, and eventually we just got different fish.
You don't have immediate funds for RO, but do you have a bit of spare money per month? It gets more expensive than RO over time, but you can buy distilled water by the gallon and mix it with an appropriate ratio of tap water to get the KH and GH you desire.