The property is an REO. The loss mitigation department is obligated to mitigate as much of their loss on the property as they can. The current strategy is to list at the BPO, then reduce the price by a few $K at regular intervals until the property is sold.
In my experience, any offer that is less than 95% of the current list price is rejected if you are using financing. Since your offer is about 85% of list, expect a counteroffer at around $133K.
Depending upon how long the property has been available, you have a better chance of having your $120K offer accepted if you are offering all cash, no contingencies, no closing cost assistance, and a quick closing (10 days or sooner). If the property has not been on the market that long, even this strategy may not work.
As far as the “rules” go, it depends upon your exit strategy. If you are planning to wholesale flip to a rehabber, then you need to give your rehabber plenty of equity in the property to be interested in the deal, so the 70% rule seems valid enough especially if you have your buyer lined up before you purchase. Holding costs are usually insignificant since wholesale flips tend to be done quickly. In this case your offer price rule might be MAO = ARV*70% - Rehab Cost - Desired Profit.
If you are planning to retail flip, then your rehab and holding costs eat into your potential profit, so your offer might need to be lower. Using MAO = ARV*70% - Rehab Cost - Holding Cost, you should have plenty of room to make a decent profit even if your rehab costs come in a little over budget.
If you are planning to hold for rental income, then your market rents and your desired cash flow dictate your MAO. If the asking price is already low enough, and the market rent is high enough, you might be able to cash flow nicely at full asking price.
If you want to use fdjake’s business model, buy at 50% FMV and sell at 85% FMV. Notice that FMV is not always the same as ARV. If you are flipping property, you nearly always make money buying at 50% FMV. If you are buying to hold for rental use, there is a price point for your market where even 50% of FMV will be a breakeven or negative cash flow.
I think the rule you use depends upon your exit strategy, and your desired profit.
Just how I see it.