hi if i use myisnipe and i enter my highest bid, is this the price i pay, the item i won was increasing by 0.50 bids my highest bid won by 7.00dollars i thought i would win by 0.50 cent margin.am i wrong, if not where do i go to fix error.thanks.

Yes, you would win by minimum bid (the previous bid + current increment).
So if you put 7.00, but the other bidder put 1.00 so your final will be 1.00 + 0.50 (if the current increment is 0.50) = 1.50.