This is my own opinion based on experience.
What i have found is that being kaamil (in the sufi sense) isnt a prerequisite to being a good Amil. Actually far from it.
Amaliyat is an ilm, and those who have mastered it (by whichever means) can genuinely help people with their issues and their work tends to yield results. Some charge, and some dont. The ones that charge shouldnt be looked down upon. They provide a service and they deserve to be compensated for their time. Good Amils sometimes dont charge the full money. They are reasonable in price too. If an Amil quotes you something ridiculous then simply ignore him and move on.
Finally going to a sufi sheikh, who isnt someone who has mastered Amaliyat, and in the process of curing you he starts you off on zikr etc is wrong. I know many people who make regular zikr and have huge issues. The medicine for Jadoo and Jinn problems isnt sufi zikr. Its whats proven from Quran/Hadith and the experience of the Amils over the years. Sometimes Jadoo/Jinns require a treatment only an Amil who has experience would understand. This isnt me belittleing sufi zikr, this is me telling you from my experience. Dont fall into this trap. Sometimes you have to nip in the bid before it gets bigger and nipping this bud isnt everyones skill.
A true sifi sheikh wont mess around when you ask them to help. If they cant help they will tell you this isnt my field. There is a story related to Sh Zakariya r.a, when a local person bought his son to him and said Hadhrat do something. Sheikh Zakariya kept insisting its not my field, but the guy said pray anything. Sheikh prayed and blew on him. The Jinni came out and started laughing at Sheikh Zakariya and said you dont even know how to blow.... she then went away. Sheikh Zakariya reply was at least our work is done who cares whether the blowing was correct or not.
Lastly, dont judge an Amil solely on his piety!! This is a confusing statement, but believe me its 100% true. You can go to someone who is scrupulous in deen and only knows a few basics about Amaliyat, these guys can generally only tell if he is affected or not, nothing more, they tell you to do whats out their in the public domain, and sometimes due to the weakness of the affected person he/she cannot do it and their problems get bigger. Going to these people can sometimes bring you good results but can also bring you very bad results. Misdiagnosing or even missing the problem is a HUGE issue. Peoples lives/families can be destroyed because the person who you thought was an expert was an amateur.
Go to an Amil who has a reputation of being a good Amil (dont be afraid to ask around), who doesnt charge extortionate fees, and who can be trusted in matters of Deen.
Incase your wondering where can i find an Amil like this? its not as hard as you think, you might need to travel outside of your locality. Talk to people. GP's/doctors in the UK are everywhere, doesnt mean they are all good, some are actually soo bad they need to be struck of the register. But at the end of the day you still call them Doctor. Same with Amils, its a mixed bag.