Both JG Lubricant Services and Blackstone Labs provide a detailed analysis.
JG gets $20.99 for a basic oil analysis and $26.99 for the advanced one. Advanced gives a few more numbers and is required for transmission fluid analysis. I think Blackstone may be a dollar or so cheaper for a basic test and they also ship the sample kit for free (you pay when you send in the sample, whereas with JG you pay upfront). For the advanced test for engines & transmissions, I think they are about the same.
Blackstone Labs
JG Lubricant Services, LLC