If you have a basic tax return then you can file taxes for free with Tax Act Free edition.
You can use the Tax Act Free version for federal and state returns, covering 1040 only.
If you need to file any other taxes that are more advanced then you can upgrade the paid version which is still pretty cheap and you can sometimes get a discount.
TaxSlayer is also another good cheap way of filing taxes or if you cannot afford that too you can try filing your taxes with CreditKarma which is also another easy and cheap and free way of filing your taxes online.
I've used CreditKarma before for filing taxes and it's very easy to use.
If you're unsure on how to file your taxes properly then it's best to hire a tax preparer to make sure your taxes are filed properly.