It's a term so widely (ab)used that it kind of lost any specific meaning.

Which I know is a hugeeee range and I am getting a little lost trying to focus it!

After getting several estimates of gross revenue from resorts within our price range, it seems like after all expenses (hoa, mortgage, management, etc.), we would be close to breaking even on most deals.  

They range from 10k-50k and are primarily located in residential areas surrounded by townhomes.

which is about 5.5 percent on my equitysecond one is a old single wide mobile home that I get about $500/month rent after expenses;  the underlying land is now worth about $175,000;  which is total equity for me, since it is paid off;  so that would be about 3.5 percent on my equityproperties right beside each other in a very hot area, which just keeps getting hotter every year, with properties harder and harder to find there.  

If you subject property is 1500 sf, you need to find comps in the 1350-1650 range (+- 10%, which can also be +- 20% depending on market and circumstances), adjusting for condition, location, amenities, DOM (days on market) is all the art portion.

In terms of rehabbing the property, the workflow can range from throwing a coat of paint on a wall or two, to an entire gut of the mechanicals, windows, siding, and flooring.

There are a few ways to go about it:Find a house in your price range with as many rooms as possible and rent out all the roomsRepeat option one but find a house that could be converted into two units - you occupy one unit and rent out the other unitIf you can find a house to convert into two units, you might want to look into the short-term rental rules in your area to increase your cashflow even more :) 

My units are larger 3 and 4 bdrm townhomes, 1600-1800 sf each, intended to serve families.With a mid-range construction budget, what items are worth splurging on to get improved rents? 

The opinion on what is a good deal varies so widely.