It is relatively easy now to assemble a solid PC. Not like back in the 80s and 90s where it could be a harrowing experience due to driver and IRQ conflicts. Now those types of issues are pretty rare. With a descent monitor, you can probably put together a descent rig for under $1K, like r00d said. If you need, I can help out. I still keep fairly well astride with PC hardware market and I have build dozens of boxes in the past.
The great part of building your own rig is you can cut out the shit you don't want, and get upgrades at at cost prices instead of outlandish markups. I'm talking to you Apple and Dell.