Puget is a good choice, but I'm not sure what you can get for 2400 or less.
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Microcenter is another. They have a lot of stores in the eastern half of the US. Very few elsewhere. You choose the parts, they assemble it all for a fee. I think you have to deal with them face to face at a nearby store.
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If you have already chosen the assembler, we could help you choose the bag of parts you bring to him.