I wonder if getting a new bike would be cheaper?

Over the past year I have had to replace wheels ($70.00 used), tires ($30.00 each), pedals ($24.00 each), bottom bracket bearing ($60.00), and the freewheel (called a cassette on newer bikes) with a used part as the new ones are not very well built according to Jae my bike mechanic. Now it looks as if I need to replace the center pull brake assemblies front and rear and because the bike is old they are special order at $40.00 each. I really should replace the front and rear derailers as they are quite worn after 25 years of shifting. They run around $50.00 each.  I have not included labor costs as I do not remember them.  I guess fixing the bike is still cheaper.  Because I priced out a Mountain Bike like mine and they start at $2000.00 and go up.  Twenty-five years ago it was a lot cheaper $300.00 for the top of the line bikes.  I guess I will keep riding my old friend for as long as the frame holds up.

Old bike rider with old bike