You may also find a nice used Superposed, 685, BL series or earlier gun, but you should know what you are looking at when evaluating these guns.
ESPECIALLY true with the Superposed, many of the 12 gauge varieties can be had for about $1500 or so - but they had an era of salt (you don't want that), will come with fixed chokes (my personal favorite and they can either be opened up or possibly fitted by Briley for thin walls, but then you are at a new gun price), but their barrels are arguably some of the best ever made from a thinness, handling, balance perspective.
If you have been shooting sporting, look at what others are shooting, not necessarily the brand, but the characteristics - you'll see 30 or 32 inch barrels, you'll see gas guns with shims allowing for better personal fit, you will see folks adding weights of various types to get better balance along with more weight for recoil reduction, and you'll see a majority of folks shooting nothing more than a 1 ounce load. Ask folks about their guns and you will have folks offering theirs for you to try - do so, and try as many as you can. Even if you fall head over heels for a 12K Kreighoff because of the way it fits and feels, and you can't afford it ...(for now), you will at least have an understanding of what characteristics to look for in a gun you can afford, a certain balance, a certain type of stock, maybe a particular recoil reducing system or forearm design, etc.
The fun is in the search, and if you buy a quality gun to begin with, your enjoyment and success will happen sooner; if you decide to get out of the game, you will be able to recoup most, if not all of your money spent on the gun. That Gti I mentioned above can be sold for more than I paid for it, thus I had the use of the gun all these years for free and I wasn't shooting something that I had to worry about breaking on me at the wrong moment - not something that will happen with a Stoeger, Yildiz or other cheap O/U.