CPA Question - 1099/S corp Associate

I'm currently a 1099 associate with an LLC and S Corp - Have to change accountants (long story) and am looking for a new one - have been talking to a few.

One is very reasonably priced. About $400 a month and will help me with my person payroll and business tax return. They are estimating I pay 20-30k in taxes by April 15.

Another firm is charging 1800 a month (!) seems insane to me... but are estimating I will get a RETURN of 20k in April...

The upfront fee scares me. Both have incredible reviews and have been recommended to me.

I want someone long term to eventually transition into a practice, my question is how can both CPAs differ so much ... is the one that's going to save me more too good to be true? Also 20k sounds crazy for the year.. just looking for asvice