I need to file a past due tax return (2017). I know I must purchase a downloadable product, (79.99) and then print a return to mail. Is this correct?

Or If you have a simple return You can fill out the blank forms for free.
Here are some blank forms & instructions for 2017
1040 <a rel="nofollow" target="_blank" href="https://www.irs.gov/pub/irs-prior/f1040--2017.pdf">https://www.irs.gov/pub/irs-prior/f1040--2017.pdf</a>     
Instructions <a rel="nofollow" target="_blank" href="https://www.irs.gov/pub/irs-prior/i1040gi--2017.pdf">https://www.irs.gov/pub/irs-prior/i1040gi--2017.pdf</a>

1040A <a rel="nofollow" target="_blank" href="https://www.irs.gov/pub/irs-prior/f1040a--2017.pdf">https://www.irs.gov/pub/irs-prior/f1040a--2017.pdf</a>    
Instructions <a rel="nofollow" target="_blank" href="https://www.irs.gov/pub/irs-prior/i1040a--2017.pdf">https://www.irs.gov/pub/irs-prior/i1040a--2017.pdf</a>

1040EZ <a rel="nofollow" target="_blank" href="https://www.irs.gov/pub/irs-prior/f1040ez--2017.pdf">https://www.irs.gov/pub/irs-prior/f1040ez--2017.pdf</a>    
Instructions <a rel="nofollow" target="_blank" href="https://www.irs.gov/pub/irs-prior/i1040ez--2017.pdf">https://www.irs.gov/pub/irs-prior/i1040ez--2017.pdf</a>

2017 Tax Tables <a rel="nofollow" target="_blank" href="https://www.irs.gov/pub/irs-prior/i1040tt--2017.pdf">https://www.irs.gov/pub/irs-prior/i1040tt--2017.pdf</a>
Publication 17 Tax Guide for 2017 <a rel="nofollow" target="_blank" href="https://www.irs.gov/pub/irs-prior/p17--2017.pdf">https://www.irs.gov/pub/irs-prior/p17--2017.pdf</a>

Don’t forget your state.  And you will have to print and mail your returns.  So be sure to attach copies of your W2s and any 1099s that have withholding on them.  You have to mail federal and state in separate envelopes because they go to different places.  Get a tracking number from the post office when you mail them for proof of filing.