Accoroding to Tetsuji Tamanaka (owner driver of team MACH, #5)'s blog,
He offered to purchase 458GT3. However, there is no answer from Michelotto yet. The reason is that Michelotto dislikes original performance tuning of GTA. (The restrictor size of GT300 is smaller than that of FIA-GT3.) He says that GTA should apply the performance tuning of FIA-GT3 to GT300.
http://ameblo.jp/team-mach/entry-10939356871.html