For example

Search the below title & note the postage costs before you actually click into the listing

ROYAL ALBERT BLUE RAINBOW TRIO music on this listing

Price $20.00 Postage $12.40 jumps to $13.50

Or

ROYAL ALBERT OLD COUNTRY ROSE TRIO

Price $31.75 Postage $16.35 jumps to $17.55

I've seen heaps of these price differences but there is no pattern to it!