You can stick to your 5% down plan, heck you can go to 3% down under fha, but you asked why sellers care about down payments because they get the same money at the end of the process and I told you why. As far as closing costs, I cannot advise you exactly on that because I don't know who pays the transfer tax in Wisconsin...I think the seller does there but here and many states it is split. I would imagine your out of pocket expenses would be similar to your ex gf, slightly less percentage wise 190 vs 180 due to the fixed nature of a couple of the costs. As far as what you do...Yes, if you think you cannot proceed by going to get an agent and getting a bank approval, I personally recommend you just rent. This is the biggest investment you will make in your lifetime, and without representation you are a babe in the woods, so to speak. You would not even know you were being screwed over while it was happening in so many scenarios. The first thing an agent would do is give you a breakdown of closing costs based on your comfort zone, it would have already occurred if you listened to me, but instead, you ask questions and ignore the advice if you don't like what you are hearing. So rent. It's a mistake, but rent.
Example: You wing it on your own. The inspector discovers that the heat pump is on its way out and recommends replacement. You tell the sellers agent, and they agree to take 8k from the proceeds and give it back to you at settlement, because you can have it repaired, they got an estimate and show it to you. You walk away from closing having only paid maybe a thousand instead of the 9k planned. Good deal? Maybe, probably not. You call the HVAC Co. and they tell you that while they CAN fix it, they recommended replacement with a more efficient model, along with the air handler, and that will be 12,599. Fix it or replace? Had you had an agent, he would have warned you about this and negotiated a better deal in my scenario, as ugly as it is.
My point is.. shit happens. It might not happen to you, and everything would go as planned, you stand in wonder as to why people pay the 4,5,6 percent to re agents when they sell. You continue to think that the pay is for finding you the right house. It is not. Realtors start to earn their pay, both listing agents and buyers agents, once the home is found and the process of contract to walking away from settlement with a happy buyer and seller begins. It starts with an honest acknowledgement that you don't know what you don't know. A good buyer agent is going to explain things to you as you go, why they are making the recommendation they are making, and importantly, ease your natural stress by handling unforseen circumstances if they arise. In the industry, they call it holding your hand.