I read recently a person can plan on spending about the same amount as they spent on their private pilot license on the training required for an instrument rating. My experience was very different.
I started my instrument training in March 2012 and did the first half of my check ride on November 1, 2012, the second half on December 3, 2012. During that time I had, I think, at least three breaks of 3 weeks or more in the training process due to illness, vacations and travel. I also had a month delay between the oral and flight portions of my instrument check ride.
I did a combination of home study and one on one ground school with my CFII at the same time as the simulator and flight training to complete the knowledge requirements of the rating. I did all but one of my instrument practice / training flights with my CFII.
Let's look at the numbers...
Simulator Time (17.9 instrument hours)
13.5 hours logged in a Frasca 131
4.4 hours logged in a Redbird
Approximately 3 hours of solo practice in the Frasca 131 not logged
Flight Time (37.3 instrument hours)
52.4 hours flight time of which 37.3 hours were simulated or actual instrument time (only .5 actual)
27.5 of those instrument hours were before I was ready for the check ride. The remaining 10ish instrument hours were from me practicing and maintaining proficiency with my CFII while waiting for the check ride and the check ride itself
CFII Time not included above
33 hours (includes ground school, flight brief and debriefs and general Q&A)
Total instrument hours to get ready for check ride: 45.4 hours
Total instrument hours from start of training through check ride: 55.2 hours
Your mileage will vary. I am happy to report this amount of time / expense was significantly less than spent on my private license.