It's easy to check, but I'll let you do the legwork. [img]/ubbthreads/images/icons/wink.gif[/img]
Surf to one of the many websites that have used-car prices. Determine about how old your turck will be when you will probably trade it in. Then check the difference in trade-in value between the two comparable trucks with the same mileage but with different options equivalent to the difference in options on XL and XLT.
Example is 1997 F-350 SRW CrewCab 4x2 with PSD and automagic tranny with 80,000 miles. The XL would have whatever options you added to it - AC perhaps. The XLT would have power everything, AC, and other items std in the XLT pkg. That will show the difference in trade-in 5 years from now. Then compare the invoice cost of the new 2003 trucks. Then come back here and tell us what you found.
Here are some websites to use for your research:
www.nadaguides.com
www.edmunds.com
www.kbb.com
www.carprices.com
www.carprice.com
And there are several others, including the big MSN carpoint site, and a Motor Trend magazine site.