I have the funds to buy another primary residence in this area but not enough for an investment property that would require 20-25%.

I promise you will have options once you finish renovating.If you purchased correctly (location & purchase price), you will have enough equity so that you can either sell it for tax free capital gains, cash out refinance (if mortgage rates are lower), or pull a HELOC to acquire your next property!

Some areas are more expensive than others but those usually tend to have higher appreciation rates. 

Quote from @Blake Johnson: It sounds like you have a great cash flowing property with a cap rate of about 16-17%.

Hands down other than major developers hedge funds and big time syndicators the biggest money in real estate today is the successful Guru trainer etc.. 

My clients are mainly real estate developers, PE funds and individual investors doing syndications and my core skill is in real estate valuation / due diligence across real estate asset classes. 

If you provide excellent housing and excellent service it is likely that your turnover rate will be lower resulting in less future vacancy.

It might mean giving up a lower rate but if you do not have the personal capital or do not want to part with it, it is the easiest way.  

Another option is to estimate value based on potential income and market cap rates, which can give you an investor’s perspective.

More control of the active income of our business due to long term rental market changes that are being effected by the rates as well as growing deal prices.