Relisting fee $3.50?

Can anyone clarify what seems to me to be an anomaly in my recent listing/insertion fees.

 

Ok, I am not a store owner and I list my items as Buy It Now.

Just recently (in last 4-5 days) when I have gone to relist, I notice I am being told I will be charged $3.50 per item relisted.

 

When I phoned and EVENTUALLY got customer service, and after lots of "ums" and "errs" I was told told $3.50 is the normal charge if relisting item (BIN) if in multiples.  I may be wrong but that doesnt sound right. 

 

I have always relisted, BIN, in multiples of 10 and only been charge $1.50 per relisting (100's of times over the last 4 or 5 invoices)

 

Sooo, my question is...... have I been lucky in the past with the $1.50 relisting fee?....and is $3.50 the real charge for relisting (Buy It Now) in multiples of 10?