Maintenance and repairs costs are a little harder to guess, but you can usually get a ball park number depending on the size of the rooms, ... etc.

Even if $645K is a "low" price, if you don't have $1MM sitting in the bank you can't play ball on their field.So if you want to test your brain, go by the property on Thursday, February 22nd. 

Shes been trying to sell it for 10 months but hasn’t had any real prospects except other investors giving low ball offers.

Well I would not advertise on craigslist personally .... if you want to maximize profit.. and you want to take it to its HBUyou can partner with a Builder..so her is the logical progression1. consult with a very good broker that sells new construction in the area and get feedback as to what would be the best bet in style size and finish's2. talk with the realtor they will know the good builders by reputation.. find a VERY reputable builder.Normally a builder if you put up the lot  and allow a construction loan by either going in partners or selling the lot on a low down payment and subordinate your note to a construction loan will do the trick.builder can give you ball park on build cost IE 100 a foot 125 foot  200 ft whatever is common in your area.with the size of home and finishes your realtors suggests and backs up with comps and you drive the comps and new construction and go through them .. this will give you Idea of what you can build.. so you will at that point figure out that new construction is selling for 200 a foot finished.. your in the deal 150 a foot and your profit is 50 a foot.. you build 3k sq ft thats 150k in profit and the all in 150 a foot includes whatever price you put on the lot. then you split profits on whatever you can negotiate with the first rate quality builders.. now these deals have significant risk.. so the reward needs to be large to do that plus you have to look at tax.. you build out its ordinary income as opposed to probably cap gain if you just sell the lot as is now which of course has the least risk

It is a nice deal but Seller has thrown a curve ball at last minute.The seller is telling me she will not be transferring security deposits to me because these are considered last months rent.This is my first rental property but I thought legally the Seller has to transfer security deposits being this is actually property of tenants.How should I proceed or not proceed?

How is that worth their time to win one crappy low-ball deal? 

Investment real estate is a whole different ball game. 

This was a curved ball and we were not sure how to respond.

(I would encourage you to fly out at least once but everyone is different) Whole other ball of wax than a long term rental but I manage 6 of them remotely with a a day job.

Gone will be that frustrating agent who comes completely unprepared & has a problem with presenting what they consider 'low ball' offers.