it really depends on the model of your pc.
But if you take it anywhere to have a professional to install it, you may look at 100.00- 200.00 Just to install it. I believe they are way over priced in fixing a few things on a pc or simply adding.
I was charged 150.00 just to install a hard drive in my dell pc.
But I learned my lesson and did research and I went and bought the piece myself, for my other pc's. research on youtube.com and i payed way less and did it myself. if you do not want to do it yourself,
you can find locations who provide you with different prices.
www.bestbuy.com in there geek squad who are licensed and have degrees doing this kind of work.
or you can take your pc to any small locations who also do it professionally.

Hope this helps.

If u knew how to install a graphics card yourself, you would be discusted on how much professionals charge and then pretend they just saved you and your computers life... Regardless if you have someone else install it for you, you should learn your computer.. YouTube it, google it. Learn every safety tips so that you aren't afraid to go inside your computer.. You'll be glad you did :)

Buy an anti-static wrist strap and learn how to install it yourself. Like the above answers stated, you'll learn more about your computer and be more capable of fixing it if it breaks in the future.

Well most new computer onboard graphic does has 256MB video memory and already support pixel shader 2.0 , if your computer is old, you can spend a decent graphic just to play sim 3 for around $50 example 3650