My property is 68' wide. The last 10' in the backyard slopes down
about 5' (10' run, 5' high). I'd like to make that back 10' flat so I
can actually use it. Anyone have any ideas of what it would cost to
have a retaining wall built? It would be 5' at the highest point, and
even though 68' wide, there isn't any slope on one side of my yard so
the wall isn't 5' all the way across, and since the slope in that
direction is pretty even I think it works out to about 2 1/2' high at
the mid point (34' or the 68' total).

My house is far enough away from the back fence that it shouldn't be a
factor (the weight of the house). I do have an in-ground pool, about
10,000 gallons, on the flatter side of my yard. Would the pool be a
factor? It doesn't seem like it would since I'm not removing any
earth from around it, and hopefully it is already held firmly in-place
by what is already there (thus it shouldn't be adding weight/pressure
on the retaining wall).

I live in Tucson, Arizona. The soil is about average I'd say, maybe a
bit on the hard side. I've found some small rocks while diging
towards the front of my property, but the back doesn't seem to be
nearly as rocky.

Just trying to get a ball-park before I go calling any contractors. I
know it would be easier to just call and get some ideas, but I really
hate people (in person anyway).