I guess, if you are not rich or have a business that generates money for you,you cannot mine bitcoin at home,due to the cost of power that is needed for mining. If you have expensive power cost,it will be a big challenge to you.

As you mentioned above that you need a cheap mining equipment, ASICs is the best and if you can't afford it or buy a new mining equipment, it is better you don't try something funny or else you will run into great lost. Mining is expensive and needs new miner for you to make profit,if possible.