Gordian 111 is a good place to start with Roman coins. You gan get a reasonably nice silver coin for not too much money.
I bid for ancients 2 or 3 times a year. Before I make a bid, I check out the 'VCOINS' website, using the search function. Coins on this site are currently for sale, so you can compare at what price you want to bid at, with a similar coin currently for sale.
You can always buy the coin offered on the 'VCOINS' website instead, if you wish.
I never buy on
ebay, not with ancients. Buying within the CCF I think would be safer. I like to see the coin in hand on the view day before I register a bid on a bidding sheet. With expensive ancients, I think there may be too many 'iffy' coins out there. Can't do that with
ebay. Mostly, I leave a bid sheet on the view day, and don't attend the auction itself. That way, I am not caught up in a sentiment driven bidding war on the floor. That way, you allow yourself to keep within a biding budget.
If my bids are successful, I feel reasonably certain that I have acquired the coin I want at a good price. If my bids are unsuccessful, I feel satisfied that I have escaped, by not paying too much for the coin. Either way, that's a bonus.
This method also allows you to still going to your job each day, without taking time off work.
I always keep all of my purchase information, if I need to prove provenance later on.