Honestly, these days I rarely if ever find myself even needing gold enough to jutify the hassle of charging people for convoluted boosting methods through LFD.
Asside from the occasional dirt cheap enchant scroll or cut gem (most of which I can just make myself), I rarely even have to use the AH. Sometimes if I am being super lazy, I will buy crafting materials to power level engineering on a new twink, but that is rarely more than a few thousand gold, and not all that often.
I probably spend more gold on transmoging than I do anything else, I just dont need gold for that much.
With that said, I do three main types of boosting on my 11 druid:
- Boosting randoms in LFD when I am bored or need a break from WF grinding, the reactions I get from people are payment enough for the entertainment value.
- Boosting RL friends through dungeons either for specific gear or XP for a few quick levels or quests.
- Boosting my alts on my second account, mostly for starting other twinks that have trouble soloing early on, or sometimes just having my level 55+ characters tag along in Chromie time dungeons for higher gold drops and vendor sales. My level 55 gets about 30g per boss kill, which ads up and more than pays for any enchants and gems I need.
At the end of the day, whatever you feel your time is worth is what you should charge.
One tip I can offer is alternate compensation like caged battle pets, or simply trading boosts or other services like crafting agreements and summons.