I build custom desktop machines, and am just now starting to sell my service. Here is how this will work:
1. You PM me with your bugdet.
2. I find a good setup for the price.
3. You say whether or not you want it.
4. You send PayPal, or money order payment.
5. I order everything, set it up, and test everything.
6. I send you the PC!
This will take 1-3 weeks depending on the payment.