We have used various methods to save up for down-payment funds: we set aside pay raises instead of consuming them, re-enlistment bonus sums, tax-free income from deployments, an inheritance check, the tax-free savings account while deployed...And so forth.  

In reality any buyer is free to do that but I don't know how often that actually happens.

I would love to buy it in just one of our names, freeing up the other name for an additional house down the road. 

Prorate bill based on previous months, look to charge other 3 tenants (the party>free ride is over). 

@Allen Fletcher is right on in his assessment of the actual tax being dependent on past use (actually 500K tax free is the top exclusion if you're married and have lived in the property for 2 out of the last 5 years) and future strategy (depending on your path you could exempt all or part of the tax in a 1031 exchange).Your accountant paints the current picture better than anyone.

Head out to one, find an investor doing the type of investing that you also want to focus on, and offer to help them for free with whatever they may need (finding deals, marketing, painting their flip, organization, etc) in exchange for their mentorship throughout your first deal.

If I can help you in anyway please feel free to give me a call.

These people usually own very little real estate or have something to sell you (their advice, a turnkey in Kansas City, or a "free" seminar)I own 19 units in Oakland and have bought them all in the last 2 years.

I even use Skype and TeamViewer to communicate with clients so I'd highly recommend looking for one of the best with great references that interviews well with you.So look for someone you can connect with that works out for your situation.Feel free to ask here if you have questions

I forgot to mention that the seller will probably not take back the mortgage, because it is not free and clear according to the RE agent.