Do the calculations man. It's simple math. What model processor/GPUs are you looking to buy? See what others have reported their hash rates to be. Figure out your total hash rate and use a profitability calculator to figure out how much you will make per day. Divide that amount into the total amount of money you want to spend on your rig and you will have figured out how many days ROI will take.
But I can tell you, spending $3,000 on computer to be used for mining sounds like you are being ripped off or not building it yourself (Unless you are getting some bad ass GPUs). I highly suggest buying the parts separately and building the rig yourself as you will save a lot of money doing that.
Just my two cents. I hope my message didn't convey a sarcastic or negative tone. I was merely trying to say that there are ways of figuring our ROI without having others do the math for you
But I can tell you, spending $3,000 on computer to be used for mining sounds like you are being ripped off or not building it yourself (Unless you are getting some bad ass GPUs). I highly suggest buying the parts separately and building the rig yourself as you will save a lot of money doing that.
Just my two cents. I hope my message didn't convey a sarcastic or negative tone. I was merely trying to say that there are ways of figuring our ROI without having others do the math for you