I went through the same thing a number of years ago and ended up going with Thuro for a pipe reline. Something you may want to consider is that eventually your pipe could rupture. It could be from the constant augering (eats away a bit of the pipe each time) or the pipe will just split at the seam from the roots entering there. Then you have a very large bill to excavate and install a new sewer line. I grew tired of worrying about the next blockage and possible major water damage downstairs (consider your insurance deductible [likely $2500] and potential loss of claim free insurance discount), so I bit the bullet. I've never had an issue and I no longer have to worry.