Why do people keep offering higher than the price?!!! (No personal info)

Hiya. I’m literally so baffled and wonder if someone can explain! People keep offering higher than the asking price on the exact same item on my page. Last week someone offered £7 if I re listed. Stupidly I fell for it meaning I got bad feedback (twice) and they didn’t buy it anyway. Now today I’ve got two more offers, one for £5 one for £6.

Keep in mind this item is only listed for £3!!!

I’m so confused if someone can explain I’d be so grateful!!! Is it scam???