Premature Partnership Withdrawal

I am in Illinois...

A friend of mine formed a group of 7 investors in order to buy a hotel property. I am one of them, who committed to invest 10%. I signed a commitment letter accordingly and paid a deposit ($13,000) to serve as escrow. We had two meetings so far. As I was told initially, this is a heavily family run business where my friend takes full control of the business (check signing etc.) and his wife will be office manager and his brother-in-law will be site manager and his nephews will also be working as well as living in the hotel. I knew all this but based on the proposals I have seen in the meetings, I thought I should stay away from this partnership. It appeared to me that there is lot of room for undue favors to his family members. I have not signed any legal attorney-prepared document yet. I recently expressed my intent to withdraw from the partnership. The purchase has not taken place yet. And I do not know if it will take place for sure. My friend tells me that I have to pay my share of attorney fee and also the application fee paid to the hotel franchise company. We have not formed a company yet as far as I know. And I have not seen any purchase contract if there is one. Following is what I signed in the commitment letter:

“XXXX (my friend) is to provide receipts and invoices as relevant towards the expenses incurred in the process. In case we decide not to complete the purchase, in such a case all left over amounts will be refunded back as per the percentage contributions above. I understand that I may not receive all my moneys back. We will make the decision on proceeding or exiting from the deal together in the period (30 days from the date of the signing of the contract) when the escrow amount is fully refundable. XXXX has full authority to make any decisions related to the purchase and is responsible to discuss the progress with us in the process”

I want to know what expenses am I responsible for?