Whenever I use a "free" plugin that I like, I usually buy the "PRO" version to support the developers. But in return I expect to receive support when I run into bugs.
W3 Total Cache is full of bugs and constantly causing errors in my WordPress site. I tried to send a support request but discovered that even for users who PAID for the PRO version, support is not included.
The only way I could get a response was to send them a "Contact Us" email from their website titled "Request for Quote". Amazing! They responded in minutes!
However, their response was:
(1) Even though I paid for the PRO version, support is not included and costs extra ($75 per email).
(2) They told me that when I signed up for PRO, their engineer had "reached out" to me to "help me get my site dialed in". They were referring to a sales pitch to get me to spend $250 to have them "optimize" my site.
(3) They told me that no one at their company ever looks at the support forums, so posting there is a waste of time.
DO NOT pay for the PRO version! The company will not provide you with any support whatsoever.