You can then piece in sections around the edges, or, you can rip your final flooring at the outer edge of the square to fit flush to the wall.

A toilet before 1980 might use 5 to 8 gallons per flush (gpf), each resident  might be flushing 48 gallons  of water daily......   

Every living unit must have at least one (1) bathroom which includes a flushing toilet, lavatory/sink and a bathtub/shower.

If they are flush with work at a certain time of the year, you are going to get the contractor's scraps as they hire out subs for everything and rarely check in on your job.

Its important to flush the drain every few yearsReplaced sump with twin pump system and battery backup with alarmTied stairwell drains to drain / sump systemInstalled dimpled membrane on wall that will divert any wall seepage to drain/sump systemDug out / cleaned window wells 3ft down and re-graveledAdded proper exterior grading, swale system downspouts and french drains

The Seller makes up for lack of knowledge by creating market competition in order to flush out a fair price.  

I have had times in my life where I've been dead broke, and times where I've been flush.

Its like flushing money down the toilet!

(Examples of improper use include overloading electrical outlets; flushing large, foreign objects down the toilet; and allowing any gas, electrical, or plumbing fixture to become filthy.)• Dispose of trash and garbage in a clean and sanitary manner.• Not destroy, damage, or deface the premises, or allow anyone else to do so.• Not remove any part of the structure, dwelling unit, facilities, equipment, or appurtenances, or allow anyone else to do so.• Use the premises as a place to live, and use the rooms for their intended purposes.For example, the bedroom must be used as a bedroom, and not as a kitchen.94• Notify the landlord when dead bolt locks and window locks or security devices don’t operate properly.95However, a landlord may agree in writing to clean the rental unit and dispose of the trash.96If a tenant violates these requirements in some minor way, the landlord is still responsible for providing a habitable dwelling, and may be prosecuted for violating housing code standards.

It can be tough to swap out fixtures while residents are living there, but when a resident moves out, I'd recommend an ultra high-efficiency toilet(the Niagara Stealth at Home Depot uses only .8 gallons per flush, half as much as a standard toilet and about 38% less than what is considered a high-efficiency toilet.)