I'm looking for a 7" monitor for under $40 USD to connect to my computer via usb or through my available display port on my gpu, which ever way providing it will not interrupt my current 3x monitor resolution.
I want to use this monitor to display Trinity's avatar or full ultra Hal program on the front of my custom pc case. eventually mounting a water filled globe with a flat surface to the screen for a snow globe effect

Please can you guys help me find one, did I say please  

I was able to find 3.5" ones like this in the link below with rca jacks, but unsure if they would work plus I would really prefer a 7" display.
http://www.newegg.com/Product/Product.aspx?Item=9SIA0U00890442

Found this site. http://www.geekstuff4u.com/computers/peripherals/secondary-screen.html

The cheapest Samsung one is out of stock though. That size of screen is more the car market, hence the RCA plugs. But there are USB devices as well.

Thanks Snowcrash, unfortunately there all above my max budget of $40.oo
I see these ones posted many times on feebay   but I'm not sure if they could be made to work on a pc  
http://www.ebay.com/itm/7-Stand-Ultra-thin-TFT-LCD-Car-Rear-View-Reverse-Color-Screen-Monitor-09-/181014768646?pt=US_Rear_View_Monitors_Cams_Kits&hash=item2a25522c06

http://www.ebay.com/itm/CAR-REAR-VIEW-7-TFT-LCD-MONITOR-/321094032667?pt=US_Rear_View_Monitors_Cams_Kits&hash=item4ac2b21d1b

I'm with Snowy here Syber, that size screen is likely to be available to the Auto-motive market and given the budget your on, maybe you should look toward the used market. 

I found a couple in the price range on Amazon UK but I don't know how or even if they could be connected to a PC.

http://www.amazon.co.uk/NTSC-Digital-Monitor-Remote-Stand/dp/B005Q6JNV0/ref=sr_1_1?ie=UTF8&qid=1363950514&sr=8-1


http://www.amazon.co.uk/Camera-Monitor-Support-Rotating-Screen/dp/B007SLDF7O/ref=cm_cr_pr_sims_t

The screens are usually for the car market, and prices I've seen seem to go from mild to wild 

@Data: Thanks for the links, I was thinking of using one of these adapters which is an av to vga
http://www.rakuten.com/prod/pc-computer-vga-to-tv-s-video-3-rca-av-adapter-cable/219946686.html?listingId=132699671
and then maybe vga to display port
https://www.google.com/shopping/product/4217500700367168320?q=vga%20to%20displayport%20adapter&hl=en&client=firefox-a&rls=org.mozilla:en-US:official&bav=on.2,or.r_qf.&bvm=bv.44158598,d.aWc&biw=1654&bih=891&sa=X&ei=mVxMUbLVDavYyAGh4IHwCA&ved=0CHoQ8wIwAA

only problem is I'm not sure if the small resolution on these small screens would alter my other screens resolution or even if the idea would work with a pc seeing the screens are made for video not pc 
Though I really don't think it matters, though I could be wrong

I've noticed the cheap ones not only have poor res they're also slow response and poor contrast ratio.

I've typically seen 50ms response (state of the art is 1-2ms, 5ms is fine) and 100:1 (1,000,000:1 is top, 10,000:1 is ok).

The slow response will cause a 'motion blur' type effect esp when graphics move quickly. The ratio will give poor colours and black contrast, they also often have poor viewing angles and the colours change as your angle changes.

Do your homework before buying.

Good eye Snowcrash 
I was not even thinking to look at specs for I was caught up in prices.

Do you guys think I would need a monitor with good specs for my needs? I want to replicate this orb in the video below


if a monitor with good specs are needed, I will have to start saving up some pennies.

I can't help but think if you can get it going for very few $$$ on a lower quality screen its probably worth a shot. the slower response time might even add something to the overall effect. If its no good at least you haven't wasted to much cash.