The 8-GB 3G iPhone will only cost customers $199 if they sign up for a two-year contract, AT&T (NYSE:T) said Tuesday. AT&T also revealed voice and data plans and what customers need to do to be "iReady" when Apple's 3G second-generation iPhone hits the streets July 11. "We can't wait to offer iPhone 3G to our customers, and we want to make sure the buying process is as easy as possible," said Ralph de la Vega, president and CEO of AT&T's wireless unit, in a statement. "Considering all the great new features of iPhone 3G, we think our pricing and monthly plans present a tremendous value for consumers and businesses alike." The 3G iPhone's 8-GB model will sell for $199 with a two-year contract to new customers and current iPhone owners, but existing AT&T customers who are not eligible for upgrade discounts will be charged $399 for the same device. New customers, current iPhone owners and those eligible for upgrade discounts can get the 16GB 3G iPhone for $399. AT&T customers who aren't eligible for upgrade discounts will have to shell out $499 for the 16-GB model. In the future, AT&T said it will offer a contract-free iPhone option for $599 for the 8-GB and $699 for the 16-GB. AT&T said it determines eligibility on the length of time remaining on a customer's current contract and payment history. Current customers upgrading to the 3G iPhone will be charged an $18 upgrade fee, and new customers will pay AT&T's standard $36 activation fee. AT&T iPhone customers can choose between the company's various AT&T Nation plans combining voice and unlimited data transfer. The cheapest, with 450 anytime minutes and 5,000 night and weekend minutes, costs $69.99 per month. The unlimited plan costs $129.99 monthly. All include visual voice-mail and nationwide long distance and roaming.