Cost savings? I'll have mine sharpened next week at a cost of $7/inch each side. New is over 200 dollars. Maybe this is where your problem starts from. Try new blades and see if the extra edge length helps.
Just got back. I asked the shop guys about your issue, said not easy to diagnose without seeing the problem.
Also, major difference in costs but similar to what you're claiming.
Just got my blades sharpened. Total cost $75.75 for 36 inches sharpened (4 sides, 9 inches each side), $2.10/inch. Cost for new set of blades, new kit including bolts, $128 so by putting new blades on you might be saving some time and time is money.
Don't know where I got my numbers for costs originally.