Plane seatbelt extenders

Hello, everyone!  I'm just starting out here and thought this would be a good place to ask a question I'm nervous about.

I have a business trip coming up that requires me to fly on a plane (something I haven't done since I was a teenager).  I am worried I will need a seatbelt extender!  If I will, I am thinking of buying on in advance.

At any rate, I am 5'7", 325, pants size 26.  Can anyone "weigh in" (ha) as to whether you needed one and what your weight or size was at time of travel? 

It's a domestic flight with AirTran (seat width 17", which is two inches narrower than my standard office chair).

Thank you so much for your time!

Instead of buying one, your best bet is to simply call the airline and ask for their advice.
Then the cabin crew can may be able fit a slightly bigger seatbelt to your chair before you get on to the plane.
Saving you a lot of worry and embarassment.
Its definitely worth giving AirTran a call!

In case anyone searches this thread, I bought one on eBay and boy was I glad!  I needed one, definitely!  I needed several inches!  I was able to surreptitiously take it out of my carryon bag and apply it, then put my jacket over my lap.  I don't think my co-worker even noticed.  When we landed, I did the reverse and had it back in my bag before anyone noticed.  That was Feb. 2010 when I was 320/ 325ish.

I'm not flying again until May 2011, which will be 6 months after my surgery.  I will hopefully not need it, and when I get back, I plan to sell that sucker!!!  :)  It was $35 + shipping- ouch!  But well worth it to keep me from having to ask for one!