It is difficult to tell. Right now i have only few hardest to find Rare Pets at lvl at lvls 23-34 right now. But how long it will take ?? It depend how many pet bags You an get .Difficult to say.
It basically depends on how much you spend as well as how many of the pet bags you get. High end players leveled their pets to max pretty quickly by acquiring the pet bags via purchases. While the purple eggs incubate longer they provide more pets per egg, you can further speed up this process by using gems for the incubation. Good Luck!
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For me, as F2P it took years to get my first one to level 35. However, if I was starting now, the normal pets would get to level 35 much faster as there are a lot more chances to get them (eggs, packs, etc.). I only just this week got my Piblob to level 26, which was my last pet I needed to get to level 26. I now have all the max bonuses in the Pet Compendium. I have been playing for 7 years and have only done 1 accumulation that got me the pet packs. So the more you try, the faster it is. If you're P2P then you can be done a lot faster.
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