in trying to keep costs down (ordering a new trailer), are there things that i can add later that won't cost MORE to add later on? 

for example, i was thinking about having it wired for a generator, but buying a generator later.  or adding an awning later.  suggestions?

This is the same process I go through when I build a new home for somebody.

I tell them to do the things that are hard to change later.  The things that are easy to add can wait for the budget to catch up.

It's hard to change the windows out later but it's easy to add a two tone  paint job later.

It's hard to brick a house later, but it's easy to change out the light fixtures later.

For a trailer, it's wasy to add a generator, Especially if it's pre-wired.

An awning bolts onto the side of the trailer. Unless you need to run power (for a power awning) it's not a difficult add on.

You can add a TV later, but it's nice to have the wiring in place.

Same for gas appliances. You can cut a hole in the countertop for a stove later, but snaking a gas pipe through is more difficult.

It all depends on what you have now and what you want to add later. For instance, if you have a bare dressing room and later want to finish it off or add a LQ, you should install any wiring that would be later covered by a finished interior. If you want additional load lights or a porch light, outside speakers or lighted assist handle, these items will be difficult to install and wire when the interior is covered.

If you are in the process of purchasing a trailer, and plan on a later LQ, you can order from most manufacturers, camper doors, windows, frame spacing for plumbing and holding tanks, A/C roof supports, egress windows in the bunk area, and walk through doors etc. You should also consider a heavier axle/wheel combination to carry the anticipated extra weight. Some DR trailers will be overweight when a LQ interior is added.

To later add these items would cost more, than during your initial purchase.

BOL Gard