Depending on how you define 'buffer' I might fall into the 'has one' or 'does not have one' category, but you invited responses from both so I'll respond anyway
If 'buffer' just means 'completed comic updates that are sitting on your harddrive unposted', then I have 3 strips worth of 'buffer' But if 'buffer' means 'unposted updated you collect *for the purpose of helping you stay on schedule', then I don't have a buffer, because I don't have a schedule (and yeah, if someone doesn't like that, they can go read something else or fork over the dough :P)
I still keep those 3 unposted strips around though, in order to psychologically distance myself from the episode I'm posting. If I post the episode I just finished, I'll feel compelled to check on it every 5 minutes to see if someone engaged with it, and that just ain't good for my sanity XD
And yeah, I also hate using up my buffer, and I don't even have any stakes attached to losing it (I can just build a new 1-strip 'buffer' by only posting after I've completed 2 new ones). I feel this hard at the moment because my 3-strip buffer is soon going to be 2 since I'll be posting a bitwam update at the same time as my call-to-action entry in order to get readers of the former to go to the latter, but I don't have a new bitwam strip entering the buffer because I've been working on said call-to-action entry :'D