Unfortunately the barrier for entry into a lower-end home is about $1 million now, and property taxes are low (likely less than $5k).I currently have a financed home with about ~250k in equity (2% interest rate), and we have about ~220k in cash. 

Land is so cheap that if you do end up buying a large tract taxes are really cheap and you could build your own portfolio of land in areas you desire. - Double closings/Assignments - As the land market is getting saturated with other investors.

What I would encourage you to do is to compare how much cash you currently have invested out of pocket in the deal and also calculate what the cash flow is for that property.Cash flow is the income (rent) minus all expenses: mortgage payment (including principal, interest, taxes and insurance), average maintenance costs, capital expenses (new roof, hvac, water heater.

Yes, you get depreciation and tax write offs.

If you have been working on it but not listed anywhere, you can't deduct any expenses until next tax cycle.Also, I would highly suggest you get yourself a CPA that can help you.

My situation is that I wonder if I can use being a real estate agent as a strategy to save on taxes by creating a solo 401k.

Let the property owners worry about taxes, insurance, etc... while you make money every time a property is cleaned plus every time someone stays in the property.  

Also, for the taxes did you have to file state tax returns in all the states where there are mobile home parks that is for the ODC fund?

I am not opposed to flipping, but I need to educate myself on the tax implications first.

My interest is this seems like a smart cheap purchase and the value will continue to rise, and it gives me flexibility to combine lots later to 5000sqft.My concern is that the home is old, i wouldnt be making any money on it monthly, and i would owe so much on these two lots that even if i sell in next 5 to 10 years it wouldnt be a huge make.