As I said in your other thread, there has to be some underlying problem as to why your beardie wont eat. It could be brumation which is normal but I would be doing force feeding as a last resort. I would be making sure the environment is correct and get him to a vet for a checkup. My vet charges $53 for the office visit/checkup, $83 for a culture, $93 for a full blood panel and for Harleys 2 week supply of Baytril, it was about $20. Don't remember how much the fecal was but as I have had Harley for 2 years and never had symptoms of parasites or anything else wrong(knock on wood) except her slight RI, I opted to skip the fecal at that time. My advice is find a good reptile vet and call them and ask them what the price is for an office visit/checkup. Once he is in and gets looked at, the vet will give you advice on what they think might be wrong and/or what tests need to be done and the prices and you can decline or accept all or part of them.
The closest I came to "force feeding" Harley was when she was on Baytril. I syringe fed baby food mixed with probiotics to her daily and that was only dripping it on her nose and letting her lick it off. I never forced anything down her throat except the Baytril which when she saw that prescription bottle come out, she took off and would run up the couch back, along the top of the couch and jump to a chair. She hated it.
Remember force feeding is going to induce stress and in an animal which is already weakened and not receiving medicine for a possible illness, that could allow that illness to fully blow up and create even more problems.
And like Cooper said, my vet gave me a sealable fecal container to take home and said if I do feel I need a fecal done, I can collect a fresh one and drop it off at the office that day. I wouldn't need to make an appointment as they have Harley of file as a patient now anyways.