Combination-Release holsters are priced about $6.00 more than Thumb-Brake Holsters, unless themed snaps are used then the cost increases a little. An example of a themed snap is the skulls you see on some of the holsters.
Ruger GP 100 Holsters
Combination- Release Holsters
All holster pictures are displayed using a Ruger GP 100 with a 4.2 inch barrel.
The GP holsters are grouped into a few different categories based on wear and retention designs. The first group are thumb-brake hoslters. They can be made in either a standard/strong hip design or cross-draw styles. Next are the combination-retention holsters. These work like thumb-brake holsters but the retention strap can be completely removed. Further down you'll find pictures of Alaskan holsters with a tactical strap sewn on instead of a belt loop. Tactical designs move the revolver off of the hip moving it down to the upper thigh. Tactical holsters can be ordered with either a thumb-break or a combination release.
Tactical holsters are the same holsters styles as pictured above with the following exception: Instead of a standard or cross-draw belt loop, a tactical strap is sewn on in their place. This keeps the firearm off of the belt line and places the heel of the revolver closer to the natural relaxed position of the palm of the hand. The tactical holsters are about $40 more than the standard hip or cross-draw holsters.
Below are pictures of holsters designed specifically for the Ruger GP 100. These GP 100 designs also fit a few other firearms such as the Smith and Wesson 686 and Taurus Trackers. I hope to have reference numbers and approximate prices in captions below each picture in the very near future, if they are not already in place.