I think you always have to factor shipping into total price. I don't sweat that too much unless it is absolutely ridiculous. BUT I will say this, the USPS priority mail rates are out of sight, when I ship from East coast to West Coast, the cost for a 3 to 5 lb box jumps to close to $19. UPS Ground is under $10 for that. The Postal service rates are awful.
Also, in defense of sellers on ebay, they are hit with listing fees, final fees and paypal fees. There has to be a some sort of handling charge to recover that especially if it is on a low dollar item. Now direct sales are different, shipping should be at cost or near cost.
My 2 cents
Tom