I'm building a high performance PC to mine while I'm away at work. I don't need anything crazy, If I could bring in even just $20 - 30 dollars a week I'd be satisfied. So like 4 or 5 bucks a day. My question is, with the difficulties what they are is this still a possible thing? I mean, if I mined using a really nice GPU would that be enough to make that amount of money? And of course I would have a decent cpu as well, but that's not as important. I'm not worried about electricity either.

Am I wasting my money building this? Is an ASIC rig basically my only solution?
Any suggestions for someone starting out? I've got a starting budget of about $200 - 300 dollars. I can increase that budget by making money once things get going.

Thanks