I was told that the dilution of my original investment would be 21.8% if I did not participate.

This is $95.Hard Closing costs - This is legal, Underwriting fee, processing fee, wiring fees. 

A genuine question here for you, who are you working with right now and how much are they charging you in fee?

Cityplace charges flat fee of $60/m for LTR.

I'll add a few more things that can have a huge financial impact: required reserves, LTC (loan to cost), application or other upfront fees, and prepayment penalties.As a fellow flipper, I think it's important to have reserves, but they shouldn't be required as part of your funding.

This would typically include legal fees, the receiver's fees and costs, and the repair costs. 

I originally looked into QuickBooks but it seemed very expensive for everything I would need it for.

The total cost for this monthly for me is $1.00 fee for online payment for Sevier County, TN and the .73 cent stamp for Blount County, TN.

The original intention was to do a light cosmetic rehab and rent it out.

One great thing about fix and flip loans is that there is no early payoff penalty, so the original lender's commission is not at risk!