Offer arrived, can I still ask for more? - 5 months and counting

I received an offer as a barista and I think the pay is a little low. I would rather hear the honest version than the polite one. The hiring manager was friendly and open. Did it backfire?

Keep everything in writing and save the confirmation numbers. It made the follow-up calls so much easier.

Most employers expect a short conversation. Mine did not even blink.