The Value Of art

Recently an old friend contacted me about helping him with his logo. this got me thinking about how to place a value on art. I'm not talking about the moden art that is completely over priced, and may or may not actually be art. I'm talking about commercial art. I'm talking about a client hiring an artist to create or modify a design for use by a Comercial business.

I left the art department I used to work for because at 28,I was maxed out on the pay scale for any position in the dept. I loved the job, but I could not continue working at the same hourly rate for the next 40 years. I accepted a positsion in the quality department, and then the it dept. What makes these two positions more valuable then that of the graphic Artist? If corporate America places such low value on the job of an artist, how can I justify charging more than $13/hr for any freelance work I do?