Well, I gave in and imported the Blu-ray Box for the first season, and the eleven manga volumes that are available. Currently enjoying the OST and Drama CD which came with BD-box, something I wish was bundled with more releases here in the U.S. or in a limited premium release. Hope to pick up the BD-boxes for season two and three soon, and the singles for the fourth season seeing as a BD-box may be some time away. Would also like the OVAs from manga volumes 6, 10, and 11, but since they are Region 2 DVDs (and the first two are OOP) I may have to skip over those.
I still want to support a domestic release here in the U.S. someday as it would definitely would be more affordable. Hopefully some U.S. anime licensor picks up all four seasons and the three OVAs whether it be DVD, Blu-ray, or combo-pack. I just want to own this great series!