Not
Are you asking if sellers are charging more for shipping? The actual shipping fee's from both UPS and PO are still about the same. What has come down quite a bit is uship pricing. You can get great deals there for the larger items. The down side to that is people are desperate for work, that is never good.
Not so much are they asking more, just if cost have gone up. I see $134 to ship a tin sign and think, "That seems like a lot to send that UPS Ground". But, I don't ship much and it's been years since I have mailed/shipped a larger sign.