I share a similar history, no real formal training, got to a point I was happy with and stayed there etc.
Recently I went on the hunt for a cheap way to improve my playing and stumbled across the Guitar Tricks website. I've found it to be really useful in increasing my theory knowledge, and you can pick and choose the lessons that interest you it comes with tab, videos and often backing tracks for the lessons and it would appear that they've been trying to update the lessons with higher quality videos. Now as with all things there is a catch, this being a subscription, it's $14 a month I believe, which equates to about £9 a month but you can cancel it at anytime and most if not all lessons are downloadable (beats paying £30 per hour when cash is scarce). There are some free lessons you can try, so it's worth a look perhaps.
www.guitartricks.comNow that I've progressed a bit further I've bought some secondhand books by good old Troy Stetina to have a crack at so we'll see how that goes.
The only thing that I have problems with is sorting out habits I've developed over the years and not adding to them. So far I have a friend who's given me a couple of pointers but I guess if you go down the "No Teacher" route you make sacrifices.