[Visuall]

I am looking to buy one, any suggestions?

[Schatten]

I'd recommend vDos but you only have $10. You should check out the Server Stress Testing section to find a good one in your budget range.

[Socreor]

Also using masterstresser.com
Best stresser ever!

[Epicguy]

purestress.net is great, you can get 600 seconds and 1 concuring attack for 9.99 (1 month only)

[Seven798]

this is a good thank you :D

[Lizard.]

I'm currently making one.
You can get 2 months and boot for 2min for only $10!