I made a counter offer & wasn't replied to. My counter has now expired - am I obliged to buy the item if I am replied to after the expire?

[homestuff*123]

I made a counter offer to a best buy counter offer and after the 48 hours I was not replied to and have recieved the notice from e-bay that the counter has now expired.  If the seller gets back to me even though it is expired - am i obliged to purchase the item?

[heidilynn0_3]

hi ..Seller must accept your counter offer to be committed. Expired means over as far as you are concerned.