As for selecting a holster for IDPA, my advise would be to buy something cheap that meets, or at least comes close to, the new IDPA rules. I can't help but to believe there will be some type of modifications to the " no gap where you can see light" rule. I have Blade Techs belt holster and it does not meet the new rules. You can clearly see light through the belt slots with it on the body. Blade Tech is advertising the holster as IDPA legal though. I know several other Blade Tech users are dipping the belt attachment into boiling water and reforming it to illiminate the small gap. Now, please do not take this post as a Blade Tech bashing. I love their holsters and have used them exclusively. Not to mention they are a great company, stand behind their products, and in my case have looked after their customers. I believe you will see some Blade Tech mods or a new holster come out of their factory in the near future that will be 100% legal. Until then, I would wait before dropping any money on the high end kydex holsters.
Some friends and I have gotten together and compared several different manufactures and models of open pouch kydex type belt holsters. Quite frankly we are having a hard time finding one that would be considered 100% legal. We are being very strict in our examinations because you don't want to pre-pay an entry fee and travel out of town to a sanctioned match only to get DQ for illegal equipment. Something that your local MD or SO might let slide may not be allowable with someone else at another event. Of all the open pouch kydex (or plastic) holsters we have looked at, the Fobus Paddle Holster meets all requirements of the new rules. It holds the gun tight to the body therefore clearly meeting the 3/4" gun to body rule. It also meets the "no gap rule" on several shooters we tested all of which were of different body size and types. The Fobus Belt holster does not meet the "no gap rule", only the paddle style. I believe the Fobus Roto Paddle would also be illegal because of it's on the body cant adjustability. So, in summary, the Fobus Paddle Holster seemed to pass our unofficial testing.
The Fobus Paddle can be purchased for around $20.00 to $22.00. If the rules change or other (read: better) holster companys change their design and become completely compliant to IDPA rules, then you will only have about $20.00 invested in a temporary holster which can still be used at the range or around the house. Take what you just read as information only. Do your own test and see what works with you. We have been trying to figure out these new holster requirements since the news first broke, and it's starting to give me a headache. My plan is to go back to my Fobus paddle holster and wait for the seas to calm down a little. The new rules have caused many waves. But, I do believe you will see things settle down a bit and an unofficial "legal holster list" will surface.
Sorry for the long read, I got a little carried away.
**Disclaimer** I do not work for nor am I associated with the Fobus Holster Company, Blade Tech, or the IDPA ( except as member). Only posting information that may assist you in making an educated decision on an affordable/legal holster.