So I was thinking, since the diamond shop has some sylesti items that the scale shops have, why couldn't the scale shop have a few items that the diamond shop has. For instance, have a scale shop equivalent of the Magical pie, called something like the "Magical Cupcake". It would increase the maturity of the pet by 1.5 days (36 hours), to scale with the difference between the lesser filters (+5 to a stat) vs regular filters (+20 to a stat), and have a 2 - 4 day cool down.
It would give those who want to speed up the maturing process of their pets, a chance to do so, even if they can't afford to purchase diamonds.