For 1000g per pet I can level your pets up to level 20, as the title say. I do that, because I like to level pets ad need more money. I don't know if the price is reasonable, if you want, I can also lower it. For higher levels definitely look here, I absolutely do not want to dispute Jupiter's business under any circumstances:
https://www.sylestia.com/forums/?thread=102586
Normally I'm not need more then 1 day for a pet. ;-)