Actually the number $7, fits well in other online marketing pricing structures. Its simple psychology - though your arguement on round numbers seems valid, $7 is less than $10 and more than $5, but since its closer to $5 - it feels like $5 to the buyer. I've learned from research that using the number 7 in a pricing structure is actually the best number to use.

Regarding actual price - I'm just guessing here. For CC3 monthly sets - how many objects on average per set? I currently have 85 objects in 3 formats for a total of 255 objects. I plan on adding the different themes which will add probably at least 80 more objects - in 3 formats, that's a total of 495 objects.

With a difference of $4 increased, does my huge amount objects add enough value to justify a $7 price, or should I go even lower?