We bought an old house and in the basement the toilet is on a platform, so that it sets well off the floor. The pipe it drains into goes into the wall about 8 inches off the floor. I believe this was done so the toilet would be above the sewage line.

It looks awful. We were first thinking we would need to have the floor dug up to install a sewage pump, but have since learned about and considered toilets w/ a macerator/pump or a wall mounted toilet. What is the best choice here? And what can I expect to spend? I'd really prefer not to have to dig up the floor to get a pump installed.

To install a wall mounted toilet, (see image)you will need to open up the wall to install a chair carrier and run a 3/4" supply to the flush valve. Get estimates on this one.
For a toilet with a grinder and pump,(see image) expect to pay around $775 plus installatioin. Check them out at;
Saniflo Saniplus Toilet with Macerator Series Pump - SANIPLUS by QualityBath.com (http://www.qualitybath.com/product~name~Saniflo%2BSaniplus~ID~60108.htm)
Good luck, Tom