It is beyond the scope of this instruction to talk about how much you should pay and how you might negotiate a good price.
In general, you get what you pay for. A cheap or free piano might seem like a good idea at the time, but once you have paid for extensive repairs the price might end up being very high.
Resale
Reputable brands of pianos retain their value better than inferior brands (kind of like cars).
While you might pay more for a good brand, you will also be able to resell for a similar price later if you decide to upgrade.
Delivery
I strongly recommend hiring professional piano movers to move your piano from the place of purchase to your home.
It is cheaper to hire movers than to repair a piano, floor, or human damaged in the course of moving a heavy instrument.
Most reputable moving companies offer piano moving services and some cities have moving companies that specialize in pianos.
In Your Home
Give your newly-delivered piano a few weeks to get used to the temperature and humidity in your home before booking a piano technician to come tune it.
To find a technician (also known as a piano tuner), ask a local piano teacher, enquire at a local music store, or find a list of local licensed technicians online.
Tuning and Repairs
Make a note in your calendar to have a technician come tune your piano once a year.
Have your piano tuned at a time of year when the temperature and humidity in your home are relatively constant (the start of the heating season in the fall is usually not a good time for tuning).
Most technicians will let you know when they notice a need for repairs to your piano. Ask for the rationale and a quote before agreeing to the repairs.