Another option is to use the "Stack" (the plumbing vent) space. It runs from basement to above the roof in (usually) a straight run, and chances are, there's a little slop in the holes through the various plates (horizontal members that the STUDS (not I-beams) are built on).
A metal (or fiberglass) fish tape is not good for long free-space runs (good for conduit or other small limited spaces). Fish tapes are bad for long, free-space runs because they have a natural curl to them from being stored on a reel .... hard to make them go straight after a couple feet. If you're going vertical, then (as mentioned above) some sturdy fishing line and a small, heavy weight work the best. Second best is a thin, straight stick (like a cheap fishing pole with the ferrules removed).
If you use a ferrous weight, then you can use a magnet to help collect the running end and get it out of the hole.
If you run the cable in a plenum (air duct), chances are it will not get hot enough to emit fumes, toxic or otherwise, but it may deform the jacketing material on standard UTP (Cat 3,4,5,5e,6) which may change the characteristics of the cable (a "bad thing"). Plenum cable would be better, but it is a little more expensive, and a little tougher to (properly) terminate (because of the stiffer jacketing).
As for having it done versus doing it yourself:
If you hire someone, make sure they are insured and bonded. That way if they break something, or damage something, or cause a fire that burns the complex into a small ashpile, they are responsible and will pay for the damages. If it doesn't work after he's done (or it doesn't certify as Category rated) - he gets to do it over, for free (most cases).
If you do it yourself, and you damage something, or burn the complex into a small ashpile, YOU are responsible and will pay. If you don't pull the cable properly (too much stretch, kinks, corkscrews, pinches, failure to maintain minimum bend radius, knots, etc) and it doesn't work well, then you get to do it again ... and pay for the materials again, and scrape up your hands again, and torq your back out again .... (I've done this alot.....),
You'd be surprised how wrong things can go when you're drilling and fishing into the great unknown space between the sheetrock....
Depending on your construction, it would probably be US$100-200 for a pro to do the job.
Good Luck
Scott