Yes, a can of Sterno should be more economical than using Weber cubes. But it takes more effort, as you'd want to obviously lift the chimney away and kill the flame prior to the coals being completely lit. (As with a gas-assist Performer, it won't be necessary to leave the flame on all the time, unless you're in a hurry or like replacing fuel more often.)
Bert
You're halfway there with the torch. But I'm telling ya, the cheap briquets DO produce more nasty, acrid smoke when starting up compared to Weber or Stubbs. And quite frankly, unless Kingsford Blue is on sale, it's not really that much cheaper than Weber or Stubbs briquets because they WILL last a bit longer.
Also, be on the lookout for something called "hardwood briquets." They'll still have a binder of course, but are nicer briquets in my opinion. Price varies, as does availability. Can't say they're any better than Weber or Stubbs briqs, but the labeling and branding tell you they are a step up from all the cheap stuff.