Welcome to the forum.
Only problem with online sales is, you dont get to do a through PDI BEFORE paying out your money.
You really want to be able to do a very through Pre Delivery Inspection before putting the money out. That forces the dealer to take care of issues you find right away. If you read thru this forum, you will find many instances where getting the rig back in for repairs under warranty takes a long time.
If you search for PDI list there are several very good ones here on this forum.
2012 Ford Expedition EL
2016 28BHBE, Elite and Thermal Packages.
Equal-i-zer 4-point Sway Control, Southwire 34930 Surge Guard 30A, Tire Minder TPMS A1A
(2) Yamaha EF2000iS Generators, Micro-Air EasyStart™ 364 (3-ton) Soft Start, Garmin RV 890, GoodYear Endurance ST225/75-15 Load Range E