Since the guitar was bought for $45 and the store sells instruments for 30% more than they paid, we first need to find out how much 30% of 45 is.
0.30*45=13.5.
Then, we can just add 13.5 to the starting price of 45 to find how much the store will sell it for.
45+13.5=58.5.
Therefore, the answer is $58.5.