Is my system worth $700 (includes shipping/tax)

Your list seems to be missing CPU & Motherboard, operating system, case and PSU at the moment.
For the same price as the Seagate 250GB 7200.10 HDD you can get the WD Caviar SE WD3200AAJS 320GB HDD. Or get the WD 250GB for a bit less.

I noticed you had an open box video card. Here are a few issues about open box items from NewEgg Knowledge Base:

What is a open box item? Does Newegg.com open box items or does the original manufacturer?
Open Box items have been opened and touched and/or returned. Because they originate from different situations, they may or may not include accessories, documentation or retail packaging. Refurbishment is done by the manufacturer. Open Box products are warranted for only 15 days. We recommend that you try out your open box product immediately after receiving it.

What is the return policy for open box merchandise? Do open box items offer any additional return policy coverage?
Newegg.com offers a 15-day refund-only return policy for all open box merchandise. Remember if you purchase a Open Box product you will receive an OEM BAREBONE item, meaning you will only receive the item itself. Accessories are NOT INCLUDED with Open Box products, even if the missing accessory is required for the item to function properly.

Do open box items qualify for rebate offers?
No, we do not offer (or honor) rebates for open box items. A rebate offer for a new product will not be honored for a open box unit of the same product.

BTW, I won't need an operating system. Got Vista Ultimate 32-bit.

I received it from my step brother. He bought it at Best Buy...I don't know much more than that. Either way, the price for 4GB is good, so if I get to use 3.5 GB, that's OK too. I plan to get Windos 7 soon, anyways.

A 9800GT (SLI card) into a AMD 790 (Crossfire) motherboard is a mis-match of sorts. A 4830 or 4850 would be a better choice if you can find one you can afford.

Hopefully you'll see some price breaks leading up to June.

So....isthis a good package?