Suggestions for Stool Test PLEASE??!!!!!

Can anybody suggest a good stool test that tests for candida, parasites, bacterial overgrowths/ SIBO.
The chiropractor im working with told me that the test she has is 502$ and i cannot afford that at all.
Are there any less expensive ones that look for all of these things?
I am really desperate at this point to figure out the root cause of my problems, and even after being on a paleo diet for almost 8 months, i have digestive issues.

Also, if i choose not to do a stool test and rather just treat my body as if it had these things, would there be any harm in taking anti-candida supplements or things that kill parasites? should they only be taken if you actually have the problems?

thanks!