With the currect exchange rate, it is far cheaper to buy directly from Japan via either Amazon.co.jp or CDJapan
I use Amazon.co.jp because I think it works better for me. CD Japan work for others. Amazon.co.jp also makes finding Yamato 2199 stuff easy since you can search for it under "2199"
With the exchange rate the cost is about $60 US dollars a disc and $20 shipping. If you get all 5 discs out now you'd save on shipping. Last one I bought cost about $78 with shipping.
Last disc will be out September 25th for a total of 7 discs.
Disc 1 = 2 episodes, but also about $10 cheaper.
Disc 2 - 7 = 4 episodes each.