If you buy an item of 30,000 the entire amount will be blocked from your credit limit (which implies that if you have a credit limit of 17000 you can not buy an item worth 30000).
However when your statement is generated only the emi for the month (30000/6) will appear as payable while the remainder amount will not be charged any interest by your credit card company, in this instance ICICI.
There will also be some amount of administrative fee from Ebay (depending on the transaction amount).
You can read the details in the eBay help section as well..
Request ICICI CC to increase your credit limit. HDFC CC is generous. I requested them to increase my credit limit and they did it in under a minute.![]()