Welcome! It's really not worth your while to buy an F-style mandolin for much less than $1,000.00. If you really want an F-style mandolin, I'd look at the Eastmans, although, I've played a few Epiphones that wern't half bad. In the under $400.00 range, I'd consider a Kentucky KM-250s or a KM-380s. In the $500 to $600 range, I'd consider an A-style Eastman. You'll have to google to learn more about their mandolin lineup. I think it's the 500 series that is their entry level mandolin.
Good luck. Check out this board cause this topic comes up fairly often and there's alot of free advice right here.
ˇpapá gordo ain’t no madre flaca!
'20 A3, '84 1N, '06 Phoenix Bluegrass, 2012 Cohen A5, 2012 Muth A5