Can I prepare a test return to compare results to CPA?

Yes you can do that.  Either in the Online version or the Desktop program.  Online is only good for the current year and will be open until Oct 15.  I think that’s a good idea.   And then you will have a 2024 tax return to transfer into 2025 next year.

You can buy Turbo Tax at several stores like Costco, Sam’s, etc.   Where can I buy Turbo Tax Desktop program?

https://ttlc.intuit.com/community/choosing-a-product/help/where-can-i-buy-the-turbotax-software/00/25893

You can buy the Desktop Download program directly from Turbo Tax here,

https://turbotax.intuit.com/personal-taxes/cd-download/

2024 Desktop System Requirements

TurboTax® Desktop 2023-2024 System Requirements

FOR ONLINE VERSION

I would start with Deluxe but if you have investments you will need Premium.

You can start Online Deluxe here,

TurboTax® Deluxe Online 2024-2025 | Maximize Tax Deductions

You can start Online Premium here

TurboTax® Premium Online 2024-2025 | Self-Employed & Investor Tax Software

Here are some differences between the Online version and the Desktop program.

There are 2 ways to use Turbo Tax.  Either Online though a browser OR by installing the Desktop program on a computer.

The Online web version is only good for one account and one return. You can log in and access your return from any computer. You only can see the forms after you pay and download the pdf. And you might need to upgrade to a higher version to enter different kinds of income. There are 3 Online versions. And you can add LIVE service or Full Service for expert help. In Online the fees are to prepare the federal and state returns (State is a separate charge) whether you efile or print and mail. Efiling is free and included.

You can see the prices and start an Online return here, 

https://turbotax.intuit.com/personal-taxes/online/ 

The Desktop program you buy and install from a download, which can do unlimited returns. The returns are only saved on your computer and can not be accessed from anywhere else. And not saved at Turbo Tax. So Be sure to save Frequently and make backups. You get 5 federal efile for free. In Deluxe and above you get 1 state PROGRAM download to prepare unlimited state returns (in that state). Each state return including the first one is $20 early or $25 to efile or you can print and mail the state for free. The Desktop programs do not have the expert help that is available to add to Online versions.

Desktop also has many other features and advantages over the Online version. You can do more than 1 return. You can see and enter into the actual forms. It has a What-If worksheet. And you can use a lower version because all the Desktop versions have ALL the same forms. You just get more help in the higher versions. In online you have to upgrade to enter certain kinds of income. Like Premium for investments.

And the Desktop program is always available even after the year ends. Which is good if you ever need to amend your return after online website is closed or get audited and need your tax records.

You can buy the Desktop CD/Download program here,

https://turbotax.intuit.com/personal-taxes/cd-download/

if you use windows desktop be aware that Turbotax has warned it might not support windows 10 in 2025. also you cannot, unless Turbotax changes its policy, download the xxx.tax2024 to an online account.

Yes, you can use TurboTax to see what your tax results would have looked like this year—even if your CPA has already filed your taxes. TurboTax allows you to create a mock return for free, giving you a good idea of what the outcome might have been if you'd filed through their software. This can help you make a more informed decision about switching for next year.

Even after April 15, you can still use TurboTax to prepare and review a hypothetical return. Just be sure not to file it again if your taxes are already submitted—you’d only be using it for comparison purposes.

If you're considering switching to DIY tax software for cost-efficiency, it’s similar to how businesses evaluate different tools and platforms. For instance, before committing to a testing platform, companies often explore factors like usability, features, and software testing costs. Doing a comparison helps ensure you're getting value without compromising on quality—just like choosing between a CPA and TurboTax.