$70 -$100 isn't really expensive for a custom made holster that will last a lifetime.
I must admit, the holster in the link
looks like a good design, and for $29, I'd give it a try. You never know, it could be great, but quality holsters usually cost a good bit more than that.
I'd rather have one good $100 holster that works, than 4 $30 holsters that only do a so-so, barely passable (or not passable at all) job.
IME...the cheap-0 holsters typically left me frustrated because they did a lousy job pulling the gun in tight for CCW duty.
Don't forget a nice stiff heavy belt. The BEST holster in the world , hung off a flimsy belt isn't going to work well at all.
If you go through a bunch of holsters that don't work...spending $70 for one that DOES indeed work, seems like a bargain.
Here's a pic of a Ruger Blackhawk IWB Simply Rugged. This can be concealed under an untucked T shirt.