McPappy are the only ones selling a brushless dyno setup, although for pure testing of brushless motors it comes with a lot of things you don't need, and still requires purchasing of all the electrics. All you need are:
1. A good balanced flywheel. Find a friend with a lathe, or get a machine shop to make one up. It's not a big job.
2. A Novak Sentry data logger (available from Novak)
3. A servo controller (a few dollars off eBay)
4. Some mounts and a safety shield (okay so you'll need some DIY skill for this bit).
5. A spreadsheet for doing all the calculations. There's a basic one knocking around somewhere from John Stranahan.
Here's my DIY unit which I built during last winter. It's been massively useful in motor analysis, ESC (boost) adjustment, gearing calculation etc.
The safety shield is vital. When I'm doing boosted testing that 300 gram flywheel is spinning at 40000RPM. If it comes off (which it has once) it could cause serious injury.