"However it is said in the Guhyasamaja Root Tantra:"
"If sentient beings commit an action As grave as the five heinous crimes He [still] can attain the superior Vajra Vehicle, But who from within disregards his master Shall never attain, even if exerted."
"That means having given up your guru, criticized the guru, or having heresy or broken samaya with one’s guru. It is not possible to explain how heavy the negative karma is from these things. One who criticizes, hurts, or belittles one’s guru from the heart will not achieve anything in this life; even if one practices one won’t achieve anything."
https://www.lamayeshe.com/advice/killing-ones-parents
Does asking a sceptical question count as criticism? Such as why the guru is charging x-amount for teachings? And giving up a bad guru is it bad? Does it matter if the guru is buddhist or not? Perhaps this only applies to certain types of buddhism?