The bags of seed should state the lbs per k for the new lawns and for overseeding. Usually 8-10 lbs per k for new lawns and 3-5 for overseeding. I am using tall fescue though. I have my own core aerator, but I charge $50-80 for that, $70-100 for seed, and an additional $40-60 for fertilizer/lime. Average yard I charge about $250.
Walker, Toro, Stihl