Just go with basic beige and white appliances, which are timeless. 

They're timeless. 

Same with décor, timeless classics rather than trendy finishes.

I'm up there in years now and I've seen fads come and go, and have dealt with different landscape issues and pests and dust flingers and accent walls, and many different types of decor and colors that all went out of style almost as quickly as the stainless steel appliances and gray walls went up....oh, I meant avocado green, no wait, I meant gray and stainless steel are the new avocado green....Anyway, if you want to go with timeless and save money in the long run, you can't go wrong with white and clean, in my opinion. 

I am the type of person that feels strongly that this is a long term investment and I want the renovations to be quality, timeless, and be a great value.

Then find themselves receiving $500 maintenance bills periodically, which kill your ROI.I've also found that a well renovated home stays rented for longer periods of time.

Nice light/medium brown oak in a flat finish will be timeless. 

If a $500 DD fee is a make-or-break amount, you likely shouldn't be playing in this market...The DD fee will generally vary based on the DD time (shorter time, less fee), risk to both sides, and price of the property.

The obvious one I understand of giving the seller the option to close within a very short period of time (less than a week).

But to me white is a more timeless look.