Well, I for one can speak on behalf of the shipping rates going up... Last year I sold a NIB Silver Diamond on ebay, and put in a flat rate of $16 for shipping. Some guy in NorCal won it... $25 to ship from rural CT to rural NorCal via UPS (it was a couple bucks less FedEx, but I have everything UPS set up on my computer...
To be perfectly honest, I have no qualms about sellers getting another $2-3 out of the shipping, because I know that if they are a good shipper, how it takes some time and supplies to do the job well (ie I always double box, some bubble wrap or packing foam, nice tape job, computer printout, etc.)
Where it does get ridiculous is these flat rates of $20 to buy a $20 blem to be shipped 300 miles away.
So is it bad to charge a flat rate? In some cases yes. It shows me its a sign of laziness and someone trying to pick up another 8 dollars off someone closeby...
But the problem is not NEARLY as bad with bowling balls as it is with other things such as books, sports cards, coins, other collectables, etc.