i live in Egypt so 300$ will be good for me and if i can do that with only 1 GPU.
Oh nononono no chance with one GPU. First ZEC isnt mined with GPUs anymore you have to buy an ASIC. You can however mine on Nicehash with a GPU and they will credit Bitcoin directly to your account. But my 1070 only mines like 50-60c per day. That would be like $15-$20 per month per nvidia 1070. It does get better when altcoin prices are rising but not by much.You would need at least 15 GPUs and at 5 GPUs per PC you would need 3 pcs. All these calculations dont take into account the price of electricity. I wouldnt recomend you to buy GPU mining rigs now even if you had free electricity. You would spend like $10 000 to mine like 300 per month. It would take too long to repay your investment. If something doesnt change it simply isnt worth it.
Here is a screenshot of the nicehash miner mining you can see the current BTC and USD$ that one GPU mines. As you can see the price has risen slightly and this can signal an ALTCOIN bull market but it can also mean that one of the 20 altcoins that you can mine with nicehash is pumping or its simply a small altcoin recovery.
Nicehash can however signal a positive move by altcoins because you are selling your hashpower to buyers which pay BTC to miners and rent their hardware. This means that if prices are rising there is confidence in the market. If I wanted to get into mining I think it would be much better to simply find an ALTCOIN (mine is zcash) that you think will rise and rent hashpower on nicehash to mine to your address. Then you sell when youre in profit. At least you dont get stuck with hardware which you have to sell later when it gets old or fails.
Buy coin directly from exchange is much more profit than GPU
Let me just add that when I was actively mining back during the bull run 2017 the most profitable months with 8 x ATI radeon 390 (Comparable to 1070) were $900. That was mining and selling coins for USDT on shitfinex as soon as they were mined (This wasnt a smart move, got Bitfinexed).
So that translates to $3.75 per day per, per a tier below, the best GPU awailable on the matket. There were only a couple of months like that most were in the $500 range so thats $2 per day per card.
You can earn much more if you find a coin, mine it, and wait for the right time to sell. This is of course speculation and can lead to losses if you choose the wrong coin. And it takes some work to follow the coins progress to guess when to sell.
As for ASICS which you need to mine zcash you must do a little research and wait for the new model to come out and buy that. If you buy the earlier version the hashpower from the new miners will destroy your profits.
With ASICSs you are also going to get used machines as the manufacturer will mine a couple of months with them to “test” (read/ profit from) them .
When ASICs are no longer profitable they are basically a paperweight and worthless where as a GPU and other components will at least retain some value.
At least you can make 2 decent pcs and have a couple of gpus left to sell or donate. I am not sure if ASICs are even worth recycling so they are extra bad for the environment even if every proof of work itself is terrible.