My Union dues add up to $610 total, not sure the refund on my taxes would be equal to or higher than the cost of $39.98 TurboTax Deluxe
You can try preparing your tax return without your union dues, then make a copy and add the dues to the copy. That way you can see if adding the dues makes a big enough difference to your return to justify the $40 cost of TurboTax Deluxe Online. Then you can file the return that you prefer.
To make a copy of your return, sign into your TurboTax account, and then find the return you want to copy. then click "Copy" under the return name. You may also want to rename the copy so that you know which is which.
FYI: Depending on what else is on your return, you may still need to upgrade. Please see these TurboTax FAQs for more information: