What to expect in terms of costs, recovery, and results with a pretrichial browlift?

There are no good reliable techniques for stretching the for it skin laterally without lifting it. If one has very deep glabellar folds, there is usually a lack of volume at the folds that even pulling the skin laterally will not flatten the area. Eyebrow distortion also limits this technique.

At 5 weeks if your brows have returned to their preoperative position, then I would agree that the operation has not been successful.  It is normal for the brow to drop partially, and the results can be subtle, but of course their should be an effect, and I work hard to have patient...

Thanks for the question. It can be a difficult topic and requires an extended conversation to go over the details. I recently wrote an editorial on this and you may find it helpful. Rather than simply retype it, I posted a link below. It is a three part editorial and you may find it helpful...

Browlifts will settle slightly lower than initial placement regardless of approach.  How much they settle depends on the fixation method used for repositioning the brows more than the approach (open vs. endoscopic).  

Relaxing the muscles in the area will definitely soften the crease but augmenting this area would probably be a more permanent solution. You have some options: Radiesse works well in that area and can be long lasting. This is probably the easiest option, but it needs to be done by an expert...