What’s the Cheapest Way to Fly to Vegas?

Reader Colm H writes:

I have an air travel question I was hoping you could help with. I
m in Chicago, a Vegas virgin, and I
m heading out there for the first time at the end of March for a bachelor party. The hotel is set, so I don
t need any package deals, but I
ve been hearing conflicting reports on airfare. As of now, the cheapest round-trip airfare (Thursday-Sunday) I can find is around $350, but I have heard from a few fellow Chicagoans that they
ve gone out there for as little as $210. I know that it
s cheaper to leave and come back on weekdays, but that is impossible with work. What gives? My friends have told me to check it everyday and it should go down. Does the price really fluctuate this much? I hope you can help, or point me in the right direction.

Update! Lots of Vegas tips out of Chicago from readers after the jump.

Cat M writes:

If Colm of “What’s the Cheapest Way to Fly to Vegas?” wants to fly Mar 30 / April 2 (I can’t tell from his question exactly which weekend he’s referring to) then he can get tickets on Southwest for about $250, roundtrip.

(I’m guessing that must be close to spring break, because most of Southwest’s good fares are ‘unavailable’ for the end of March — there aren’t any good fares for the Mar 23/26 weekend.)

BG writes:

Allegiant Air.

Flies from Rockford, IL to Vegas (non-stop, mind you) with outbound fares of $149 on 3/16/06, $119 on 3/23/06 and $89 on 3/30/06 (all Thursdays). Return fares on 3/19 of $179, 3/26 of $89 and $119 on 4/2/06.

Flights get into Vegas at 1:45 local, and leave very early (6 AM Vegas time) on that Sunday. Returning on Monday is a slight bump on the 27th ($119), but cheaper on the 20th ($149 versus 3/19) and on 4/3/06 ($89). These are 6AM departures too.