Vortex will likely be the best for FFP but for F-Class I'm guessing you want high mag and SFP is fine? Thinner the reticle the better? Nightforce makes a scope that isn't too pricey and can probably be had used for somewhere around there. Forget the model, it's SFP though and they have 'em in high mag ranges. Is it the NXS? Not the ATACR models though.
I just got a Viper PST 1-4x and for a $350 scope, it's damn fine! I was impressed. I bought it to be a nice scope for a custom integral 10-22 and it sure delivered. Only complaint is I wish it had .25 or even .1 turrets instead of .5, but it wasn't designed for .22 use originally. And it would make a great optic on a more serious caliber rifle. The SFP reticle isn't that big but it isn't that fine either. They come thinner for F-class.
Lots of high end mfg.'s make cheaper scopes, like Zeiss, Steiner, etc., but some are only good for hunting, many are missing features you may want or may not need. Many are SFP. If you can find one that suits you, that may be a way to go --if you don't need a bunch of options, then there are likely a lot of good options.
Go to Eurooptic and Optics Planet and use their filter to find what you want, to narrow it down. Try to put the minimum of info in it or else it eliminates some possible candidates by accident. Try different search parameters if you don't see what you are looking for, because it's there.
A really great deal can be had on here from time to time, depending on what you are looking for. Lots of high mag scopes. An older, high end model with less features may be just the ticket.