Developers may finally be seeing some relief from the summer’s high user acquisition prices reports Boston-based user acquisition and marketing company Fiksu. According to the company’s latest figures, the cost to acquire a loyal iOS user — defined as someone who will open an app at least three times — fell by 16 percent in September, hitting the lowest price seen since Apple’s offer wall crackdown.

While many had predicted the iPhone 5 launch would follow the precedent set by the 4S, which saw user acquisition costs hit $1.47, the price actually fell by 21 cents, hitting an average of $1.13 for the month.

The last time the Fiksu reported numbers this low was in May 2011, when Apple’s ban on offer walls dropped user acquisition costs to $1.10 per loyal user. User acquisition costs took a similar dive in January 2012, falling to $1.14 after the holiday advertising frenzy subsided.

According to Fisku CEO Micah Adler, app marketers did a much better job planning their iPhone 5 launch advertising campaigns than they did for the 4S, a move that allowed them to pick up new users more cheaply than anticipated.

“Brands held off on advertising in the run-up to the iPhone 5 launch, then jumped into the fray as the phones hit stores and mailboxes,” he said. “Despite the increase in advertising volume and CPCs, marketers who went after these new users were rewarded with a nice drop in overall costs for acquiring loyal users.”

On the download front, Fiksu found that the volume of free app downloads per day hit 4.07 million during September — a slight increase over August’s 4.05 million. That said, the company reported a clear delineation in download activity before and after the launch of the iPhone 5. Downloads for the month were actually down three percent before the iPhone 5 began arriving in consumer’s hands on on Sept. 21, but jumped by 33 percent after launch. One Fiksu clients reported a 20 percent increase in organic downloads and 35 percent revenue gains during the post-launch period.

Overall, Fiksu’s report seems to indicate that mobile marketers have gotten much better at planning for significant events like the launch of the iPhone 5. While download volumes and user acquisition costs are likely to rise in October, overall the costs should be lower year-over-year.