Which pump groups are reputable? Is it worth paying to get in some of them? Anyone have links?

I'm looking to figure out the resale value of this build I put together last January. Thanks for any input!

Case: NZXT Source 530
Mobo: Asus Z87-A
PSU: Seasonic 850W
CPU: i5 4670k
CPU Cooler: Corsair H60 Liquid Cooler
Ram: 2x4GB G. Skill, red heatsinks on them
GPU1: Asus R9 270x DirectCU II 2GB
GPU2: Sapphire R9 270x Vapor-x 2GB
HDD1: 120GB Intel SSD
HDD2: WD Blue 500GB
Random old DVD-RW drive
Some pci-e wireless card

I just put the same build together on pcpartpicker and it came out to around $1300.
Am I crazy or are not very powerful PC's selling for pretty high prices on ebay?

I'm looking to buy 1.75 BTC with paypal to buy another type of coin. I know that people get scammed with paypal but is there some way that we could use and escrow service to make the deal?

Hey guys, I'm wondering if it's possible for me to undervolt my 270x's. I have an asus DC2T-270x and a Sapphire DUAL-X 270x. Has anyone been able to undervolt these cards? Is it even possible? Is there a guide for them? Also, I'm mining an X11 coin if it makes any difference. I know X11 uses less power than Scrypt but any less power used is fine by me 

I ordered a couple of Antminer U1's just to play with and I'm wondering what mining software would be the best to use. Is there a good guide on how to set them up?

Also, in the amazon review by DJ Knight he says he was able to overclock them to 2.5 GH/s using AntGen. Is that not safe as they only say to overclock to 2.2 GH/s? And where would I find the newest version of AntGen? Or should I not use it? Here's the amazon page, http://www.amazon.com/Bitmain-Antminer-Block-Erupter-1-6Gh/product-reviews/B00HIUIGDI/ref=dp_top_cm_cr_acr_txt?showViewpoints=1

I posted this in a different forum section before I found this one D: sorry

I ordered a couple of Antminer U1's just to play with and I'm wondering what mining software would be the best to use. Is there a good guide on how to set them up?

Also, in the amazon review by DJ Knight he says he was able to overclock them to 2.5 GH/s using AntGen. Is that not safe as they only say to overclock to 2.2 GH/s? And where would I find the newest version of AntGen? Or should I not use it? Here's the amazon page, http://www.amazon.com/Bitmain-Antminer-Block-Erupter-1-6Gh/product-reviews/B00HIUIGDI/ref=dp_top_cm_cr_acr_txt?showViewpoints=1

Thanks for any help