Co's in loveland, mount and road-force balanced my winter to summer tires (all 4) for $105. I don't trust discount tire. I least feel that BMW would be easier to deal with in case of damage while mounting (though that is a stretch). At $425 x 2 = $850 + tax? + shipping + mount/balance, $970 is on the high side, but unless you find someone to mount road-force balance for 2 tires for $25, you aren't going to save very much...
2011.5 E92 ///M3 Space Gray; Fox Red & Blk; 6MT; ZCP; ZCV; ZP2; ///M Performance Exhaust (sold)
2012 VW Jetta TDI Silver (sold; no longer commuting)
2002 Subaru WRX (sold)
The World in 35mm