You don't need to pay for par times if you are simply looking for the differences in track speeds between various tracks. Go to
http://www.americanturf.com/equalization/ where they have an equalization chart for all tracks, which is updated yearly. Can come in very handy. Another thing you can do is check out
http://www.drf.com/events/3-year-best-time-chart for a DRF 3 yr best times chart for the various tracks. I personally prefer the chart from American Turf Monthly.
On the other hand, you can also make up your own par charts for your favorite track(s). It's a LOT of work, but also teaches you a lot about how horses at different levels run.