AFAIK, there's basically no performance difference betwen a super-expensive quadro card and a $150 geforce gaming card:
This may change with newer versions, but I wouldn't spend that kind of money without being sure it's not a stupid expense.
After reading this, I did some research and found the following.
This does appear to open up a lot of cards, but it's not like the entire Quadro line is now outcompeted by a $150 card.
I'm looking at the GeForce GTX 680 as an alternative to the Quadro K4000, but I'm wondering if that extra 1GB of memory in the K4000 will increase performance by 33%.
As a hardware engineer, developer and consultant (for 25+ years), I've heard that before from so many people - here's what it translates to: "I have a Chevy Cavalier that'll do 120mph. Why do I need a Corvette? I can run just as fast as them on the road.". Then, 1 hour later "I don't understand why my Cavalier blew up."
The Quadros are more stable, more efficient and have better drivers. They are for *creating* content, whilst the GeForce cards are designed for content playback. All the little gamers out there are screaming that their little gamer cards are just as good as the Quadro, but have dead cards 6 months later. They aren't designed to be pushed to the edge continuously - just in short bursts.
There's obviously more granular reasons why high end gear is what it's worth. I'd take a Supermicro workstation board over any Asus "workstation" board. I'll take SCSI and SAS over any SATA. I'll take ECC RAM over unbuffered. I'll take Panaflo, Nidec and Delta fans over any gamer box Thermaltake fan - faster, doesnt' fail and higher RPM capability. I'll take a solid rolled 16Ga steel case over some pretty plastic gamer case with windows - the shielding is better. And, I'll take my Wacom Intuos w/ mouse over any "high dpi" gamer mouse.
If you're playing around with your computer, then anything is fine. But, if it's something you want to rely on day after day, get the job done and the money made - buy gear that isn't designed for gamers. You don't want the vid card to be the weak link in your HP workstation - don't put cheap tires on your high performance car.