An escort wagon would probably meet all your goals. I believe the 90's models have the 1.9L SOHC engine and came in automatics. 4 doors, space in the back to move things around and mpg in the 29-40 range depending on how you drive. Price would be between $500-$2,500 depending on condition and it's FWD so you can still get around relatively well in all seasons.
Known issues? cooling system issues, and electrical system issues. Make sure this vehicles radiator and thermostat are up to snuff. Check the date on the battery, and make sure the fuel pump and starter function properly / and quickly.
If you settle for less mpg, and need AWD for some reason late 90's Subaru Legacy and Outback wagons are plentiful. They are more expensive due to the AWD, and overall quality but can come in automatic, 4 doors, with the wagon rear for your belongings. with mine I typically see around 31 mpg highway, and 27 mixed. (empty car no passengers.) Price would be in the 1,500 - 4,995 range depending on year and mileage.
Known issues: 2.5L outback wagons almost all had the headgasket fail at one point or another, or are about to. Typical mileage for replacement was every 60,000 miles or so. If you are looking at this type of vehicle try to find the 2.2L Legacy version instead - no known issues that I can think of other than possible hydraulic lash adjuster ticking until it's warmed up which is no big deal.
Here's a photo of the 98 Legacy I have currently, they aren't bad looking cars either I prefer the looks and utilitarian nature of the AWD over the escort wagon since I have 2 cars the Legacy is used primarily in inclement weather and the winter months only.
Pic:
I picked that 98 legacy L wagon 2.2L up with 160,000 miles for $1,500 on a used car lot. I have since driven it across the country and back (NJ-MN / MN-NJ straight 24 hour drives at a time with no problems.) currently 184,000+ miles and runs / drives like new.
There are other great choices out there as well between $500 - $4,000 such as an accord wagon (if you can find one) or even a Saturn wagon, although having owned 4 escorts, and 4 subaru's I tend to be a bit bias in my reply since I have had good luck with both vehicles. (just make sure they are 100% sound when you purchase them and all mechanical maintenance is up to date such as timing belt / water pump.)
Hope that helps a little! Good luck in your car search!
(Edit, thanks for the 2.2L correction jojo)