How can I buy it. And to be sent to Bulgaria.

Dont buy this if you intend on using an internal hard drive. The player does not have the power management ability to stop the hard drive, so it will constantly spin even when powered down. This will eat a lot of electricity and cause your hard drive to die significantly sooner.
Only option is to unplug it when not using it, which will also damage the hard drive since the head wont be parked or platters stationary when you cut the power.

NO DTS passthrough !! Only downmix . No cyrillic subs ! No spdif - optical or coaxial !

Same model as Yangxi H2 1080p DTS Player, chipset AMLOGIC 8626H:

2.5" SATA HDD

Card Interface: SD/MMC/MS
Video interface: CVBS/YPbPr/HDMI(up to 1080p)
Audio interface: Stereo;
HDD file system:FAT32/NTFS
Video: file container: MKV, TS, FLV, AVI, MOV, MP4, MPG, DAT, TS, M2TS, RM, RMVB
codec: RM/RMVB, H.264, MPEG1/2/4,DVIX, XIVD to 1080p; DTS and DOLBY audio decoding
Subtitle: SRT\SMI\SSA
Audio Playback: MP3,WMA,OGG
Picture Browser: JPEG/BMP
Flash Playback: SWF

Video Support:

MP4, MOV (.mp4, .mov, .xvid, .m4v)
DivX, MPEG-4 @1920*1080

AVI(.avi, .divx)
MPEG1, DivX, MPEG-4, H.264, @1920*1080

MKV (.mkv,xvid)
DIVX, MPEG-1, MPEG-2, MPEG-4, H.264 @1920*1080

RM, RMVB (.rm, .rmvb)
RV8, RV9 @1280*720

M2TS/TS
MPEG1, MPEG2, H.264, @1920*1080

DAT, MPG, MPEG(.dat, .mpg, .mpeg)
MPEG1、MPEG2 @1280*720

VOB (.vob)
MPEG1、MPEG2 @1280*720

*WMV,VC-1 not support