It’s called inflation, more money printed then what is available in terms of items wanted, the BEST and only viability, skill your toon to build the items yourself.
Example; if I bought the items I was looking at it would have been about 18 mil + off the market, I bought the raw material that I can’t make myself , about 4 mil and change, I saved about 13 mil isk.
Everything is debatable, buy or build, skill and time or buy and inject, game style is highly dependent upon a persons personality which determines a persons actions or lack thereof.