Only a few weeks after overhauling its unlimited phone plans , AT&T has added a new plan to the top of the lineup that offers more data and performance -- for a higher price. The AT&T Elite 2.0 plan is available now. For a single line, Elite 2.0 costs $110 (plus taxes and fees). As more lines are added, the per-line price goes down. AT&T customers can mix and match plans on an account, but if we assume everyone is signing up for the Elite 2.0 plan, the costs break down like this: • One line:  $110 • Two lines: $100 per line, $200 total • Three lines: $85 per line, $255 total • Four lines: $75 per line, $300 total • Five lines: $75 per line, $375 total To compare it with AT&T's next-priciest option, the Premium 2.0 plan costs $90 for a single line, or $55 per line on an account with four lines.…