Hi Allen, welcome to Wholesaling! Based on some of the information you shared in your post, is it safe to say you aren't working with a mentor? I can't stress the importance of value you gain from working with someone who has a lot of experience with wholesaling when you're first starting out. Starting out, we split the profits with our mentor and figured it was better to get 50% of deals versus 0%. Go to REIAs, find others here on BP who do wholesaling in your area (through the network tab http://www.biggerpockets.com/meet), and try to learn from others who are already successful in this business.
Have you been on the inside of the property? What are the repairs that are needed? We use J Scott's estimation of repair costs that we found in his book http://get.biggerpockets.com/flippingbook/ but since you are under a time crunch, I can send you another resource we were using before that gives estimates based on square footage of the house, the type of upgrade being done, etc.
As for ARV, if you don't have access to the MLS then you might try looking on active listings to see what properties are going for in mint condition in the same neighborhood. This is what we did before we gained access to the MLS (through being licensed). Keep in mind that properties rarely sell for the listing price so assume the sold price will be about 5k less (sometimes much more) than the asking price. If a property in top-notch shape has been listed for several months, it's probably safe to say they listed the property for too much. A better way is to review the sold listings, but without access to the MLS, you will need to rely on sites like Zillow that shows "sold" properties nearby. Since Zillow isn't as accurate as the MLS, I always adjusted their sold values by about 10% - so if they say a house sold for 100k, I'd be a bit more conservative and use 90k as my ARV. You could also just get in touch with an agent and ask them to run comps for you. They may get tired of this if you bother them constantly with requesting comps without offering to pay them a small fee. Doesn't hurt to ask what amount they'd feel comfortable with, maybe$5-10/comp?
Are you assigning the contract or purchasing the property with your own cash and then re-selling it?
I hope this is enough to give you a little guidance.