in the Mid-Atlantic of the US and have twelve 4ft x 8ft (1.2m x 2.4m) cedar raised beds that have rotted out and need replacing. I'd like to find something that will last longer than the cedar but also not cost a fortune for so many replacements. I've looked into Birdies, Plastic Forests, Trex and similar, stone, and untreated cedar or redwood. Anyone have suggestions for a material that's safe, long-lasting, and cheap? Tall order but I'm out of ideas and trying to keep this within a reasonable budget. Cheers!