See the details on Bax’s blog: http://www.baxcoen.com/
I’ll just note that as usual, for the amazing quality, the price of 890L$ is extremely reasonable.
And here's an important bit from Bax’s blog :
Using the Collision Bone Deforming method is not officially supported by Linden Lab™ which means they will not guarantee that future technical changes to the SL™ viewer won’t affect existing items that use this technique.
In response to these issues we decided to additionally offer the common standard Mesh sizes for the BAX Regency Boots. This will be a free add on/ update provided as soon as they are manufactured, following the initial release.
The SLURL: http://slurl.com/secondlife/Boots/162/125/29/
Have a great weekend!
Deirdre & lelo