Peter, My Holy Grail in cheap mandolins is a Gibson Army-Navy. I believe the one I owned was built during WW1 specifically for service men and distributed in PX's. It was very loud, very bright, and very playable until the top started caving in. After several attempts at restoring it a very competent local luthier put a heavy cross brace in it and it wasn't the same so I traded it off. I paid $200 for it and would buy another in a heartbeat if I could find one in decent condition. I now play a Flatiron 2 which was modeled after the Army-Navy. I've had it 8 years and it's sound is getting better but it still can't rival the old Gibson. The Flatiron is very solidly built(made in the USA, if that means anything to you) and I paid $350 for it used.
Kentucky makes some nice sounding A style round-holes in the sub $500 class. Made in Japan and imported by Saga. Good luck with your hypothetical shopping trip. Jon, Gibson A models are not exclusively roundholes. I use to play an A50 with F-holes and a big gnarly pickup at the end of the fretboard that was never used. The A designation is more a description of the body style. Maybe some of our resident mando experts can chime in here with more info.
I'm currently looking at Peterson (Level 2) Octave Mandolins and Bouzoukis at the Elderly website. They both go for $1150 new. Can anyone tell me anything about either of these. Regards, Frankie