I hope someday and eventually will buy 1 piece antminer S7,

Keep your chin up and you can make it happen. I started with a cheap video card slowly (
slowly) mining LTC back in the day, then eventually scratched everything together to buy a ... 1.5 Ghz BTC miner (maybe it was 5 or 10, I forget) and worked my way up from there. Re-invest everything you have and exercise patience and you'll make it!