If I have majority w2 (99.9999%) income but one small 1099 income why should I use the self employment software and not the regular deluxe

[PeterM]

If you do not have any expenses that go along with the 1099-MISC that you received, then you can get away with using the Deluxe version. However, if you have any expenses that you incurred that you planned on deducting, then an upgrade to the Self Employed version is necessary. The Deluxe version doesn't support the ability to enter expenses relating to businesses.

Please keep in mind that the cost of the upgrade can be deducted on your next years tax return as Tax Preparation Fees.