https://www.carolinashootersclub.com/threads/arsenal-sgl-21.337237/
Here's what you want if it isn't already gone. It's a nice Russian rifle that will only go up in value. There's also 4 Chinese flatback mags with it, which are $30-40 a pop.
Other than that....
With your budget, I'd get a milled Arsenal. Something from the SAM series.
Milled receiver limits furniture options though, so if you want to trick it out with a bunch of tacticool stuff, your options would be more limited than on a stamped rifle.
The 7SF model has a folding stock with a longer length of pull if you need it, but there's not a whole lot of options for replacing it, so if you get one you're mostly married to that stock.
The 7R has a standard fixed stock- you'll have more options for replacing it, but still not as many as a stamped rifle.
Vepr FM's are nice rifles, built on RPK recievers in Russia, but they're front heavy and you're limited again on furniture and stock options.