SPRINGFIELD — The cost of renovating the north wing of the Illinois Statehouse will be more expensive than officials initially estimated.Only one bid came in for the project, which is about to get underway. CORE Construction Services of Illinois Inc. priced the job at $243.5 million, well over the $170 million that was originally estimated.“Despite initial interest from multiple contractors on this project, only one firm submitted a bid while the others cited the difficulties of the current construction climate …