They are milking the used avionic market dry and spare parts are gold plated.
I work in an avionics shop and I can't believe what we are charged for parts by the suppliers. Our mark up is low as its crazy pricing already.
Old avionics from the 70's has seen its day. Manufacturers are out of business or no longer supporting the junkers.
Yeah we discount hours, we do offer warranty and we do fix our f**k ups for free. Also we get paid lower than an auto electrician :-/