Learn from this. The cost of running a bike is small but there is one. You need to replace things before they wear out and you need to make yourself a maintenance schedule and do the jobs on it or get someone else too.
Sounds rescuable with your main cost being the chain, cassette/freewheel and chainring, I bet the wheels just need a cone adjustment and a good tune with spokes replacing. If your man who does the maintenance can tune wheels and replace spokes, I reckon you could sort this for less than a hundred.