Mage is definitely a crappy solo class , I guess that's the price of absolutely insane damage.
2k+ sigils is the price of that insane damage.
Lies
I'm not saying mages don't need the sigils but they are not required , certainly not that many in order to do insane damage .
As a firemage, there are very few periods to let sigils tick. Therefore, it is necessary to have a large amount in order to spend the least amount of time not casting.
In my current build, solely depending on eboost for energy and all points in focus, I am just able to "break even" with energy. In this build, I am not able to out dps rogues and rangers and I am about even with a druid. This is, of course, without any lures (besides my lure of fire) and no haste elixers.
Mages can do some great damage but to be "insane," you need a large amount of sigils. During casting (assuming I am at a boss) I would get a break of one tick for sigils every 15 secs. 50/40 firebolt costs 273 energy, 40/40 firestorm costs 431 energy, 46/40 lure of fire costs 227, and 38/40 fire attunement 207 energy. Using the dl skill may also mess up the timing.
I would start raging about losing attunement and eboost...armour.... Too much.... End rant.