best edging for the money, when you need 30'? Two 16 foot sticks of powdercoated aluminum edging. Forget plastic edging. You'd think something made of recycled dinosaurs (petroleum) would be awesome, but plastic edging is universally crap.

Another possibility ... consider dividing lawn from bed with a brick or paver mowing strip (embedded flush with the lawn grade and installed so as to have an 8" line width.)

Thanks! I'll look into both those options!