To be honest, instead of using a hard inquiry. You may be better off simply applying for a new credit card, at a different bank.
Especially, if you're making this TV Purchase, on credit... and don't have plans to pay it off immediately.
I know from the little mailers that..
Chase has a bunch of 15-Month Zero APR offers currently. And Citi has a card with 21-Months zero APR. I think Discover also has a similar offer at the moment, as well.
That's something you should definitely keep in mind. Because the 5% Discount on the purchase, is not going to make up for what you pay in interest, in the long term.
With that said... if you're planning to make this purchase and pay it in full at the end of the month. Than... go ahead. It's probably worth it.. to call Target and get a credit line increase, especially.. if you find yourself spending a lot more than $300 a month in your store.
Also. Don't forget. You could also use the Target Debit RedCard... as well. It'd pull straight out of your checking account, and you'd still get the 5% Discount too 😉