This is why I love bigger pockets over 10 different users commented but it only sounds 3 have ever done a deal before. I dont mean that in a bad way, just take everyone's advice with a grain of salt (i guess i said that right) including mine.
1. Lock this deal up, give your self some due diligence time and figure this out while you have it under contract. If you cant figure this out before you can secure the finances atleast you have the option to wholesale it.
2. Call every lender in america until you get some one that will fund your deal. Get all there terms and fees before you take money from anyone.
3. I would never take on a flip if i could not personally afford $2,500. If you dont have $2500 PLEASE wholesale it and be done. if things go over budget, if you have to make draws on the rehab, if you have small fees that your responsible for, if if if. if you dont have $2500 liquid cash either find it or walk away.
4.Find some cash. the name of the game is get the deal done. Ask friends, family, co-workers, any one that will float you some cash so that you will have it IF (more like when) something unexpected occurs. offer them equity, interest monthly or for terms.