It's not about the price, it's about the quality of wire. The magical $150 interconnect doesn't exist, contrary to what many wish were true. When the quality goes up, price will follow.
Conversely, a cheap, unrevealing interconnect on the phono stage is going to marginalize any upgrades made to the cartridge because the front end is producing more fidelity than the cable can transfer. The system's owner thinks the new cartridge is not worth it and becomes frustrated because his expectations weren't met. It's all about system matching. If someone put a $500 interconnect on a system with zip cord radio shack speaker cable, they'd be disappointed as well.
Chris