You don't need immigration companies to do any of the process. I did everything on my own. What i believe in is people who have done themselves have much more credibility in front of the offices as it shows that whatever documents they have provided are legit. And nowadays even the officers know that immigration offices do make up a lot of things themselves. I had asked for an immigration consultant to do my PNP but she was charging $5k for it, i just walked out, because BC PNP is an employer driven program. Everything is needed to be done from the employer the consultant just acts as a data entry people to fill in your documents.
Now i am doing my PR file and doing it myself. Everything is clearly mentioned in the guidelines, and if you have any questions ask the people who have gone through the process. Thats what i did.
All the best!