If you like the Glock, that's a very fair price for one. I am a Glock guy, but not everyone likes them. Have you shot one?
Thigh holsters suck for any kind of extended wear, especially if you are walking. I used one for about the first month here in country, and it became an instrument of torture. I am sure they work fine for SWAT call-outs that last a few hours and don't involve a lot of movement, and they look cool at the range on the leg of a mall ninja. But I quickly moved my pistol to my body armor, where it is vastly more comfortable. When not in armor, I use a shoulder holster.
Have you considered attaching a holster to the waist strap of the pack?