You haul, so you'll need need a truck or trailer unless you have a van or a BIG SUV - the panels are 65" x 39" and weigh 41 lbs.
Minimum of 10 (2300 watts) panels for $650 - $65 each, good price when new 100 watt panels are $85-$90 each. Pallet of 24 (5520 watts) for $1400 - $58.33 each. Panels are listed as being 95% or better of rated output and you can take your meters and test them there..
10 panels would be 410 lbs and probably OK in your van or SUV - if they fit. 24 panels would be about 1000 lbs with the pallet so that would need a truck or trailer.
Panel aging specs: 10 year warranty minimum 90% of rated output; 25 year warranty minimum of 80% of rated output.