Like many of these places, it had nothing modern inside; we installed a bathroom, basic kitchen, etc. 

Get a well dug, or install a water tank.

Wondering if anyone knows if buyers will care about it, and if I should just install now.

I install irrigation systems , I just checked prices for my zip code , Its way off , But I wish I could get what they were quoting . 6 jobs and I would be done for the year .

Lets says worst case it needs a new piece of plywood, 40 bux, and one sq of tile ( its 10 x 10 so should be more then enough ) thats 120 bux, If this makes your deal no longer a deal, well then it wasn't one to begin with.

The tread is cut to fit then I install aluminum stair nosing on top to secure the tread and prevent slipping.

With that being said, these are high quality energy efficient windows that were purchased and installed about 5 yrs ago and qualified for a rebate.

(Made up example: I like to install a cupid fountain in the back yard because tenants will pay $50 more a month for cupid statues)2- What is your favorite improvement you like to make to your properties to increase the durability of your property.

If the difference in price is much larger than the cost to install a new bathroom & they are selling faster then put in the bathroom.  

Here in the glorious "tenant friendly" (please, please, let's not be so harsh to use the term "anti-landlord") state of MA, my understanding is that it is ILLEGAL to collect anything more than the following in advance: 1) first month's rent, 2) last month's rent, 3) a security deposit in an amount not to exceed the first month's rent, and 4) the purchase and installation cost of a new lock and key.