I haven't looked for an M1A in some time so I can't be sure but my first thought is that you will be hard pressed to find anything for less than maybe $1500. I'm not sure you can even find a Polytech for that anymore. Gunsamerica had listed a PolyTech M1A with a Fulton upgrade (brings the receiver up to the correct hardness spec and adds all US GI parts) that didn't meet the reserve at $1400.00
Check out this thread about PolyTech M1A's
http://forums.gunboards.com/showthread.php?p=339081
The new Springfields are expensive as well and most now use lots of cast parts etc. Traditional old school thought says that's not great but maybe that's true and maybe it's not.
IMHO your best bet is to save a little more money and look for something with a receiver known to be in spec and all GI parts. Nothing wrong at all with a Polytech. Most will tell you that an origional Polytech is a great value today if you can find one. (especially if it's been brought up to spec by Fulton or someone else.)
My M1A is a 5 digit Springfield with a TRW bolt, H&R barrel and all GI parts. It has a trigger that's silky smooth and breaks like a glass rod. I have no idea what it would go for if I wanted to sell it but it's worth a lot more than $1500. At least to me.
An M1A is something you will pass along to your children when you are gone. Spend the money up front to do it right if at all possible.
Good luck in your search!!