someone help. I'm trying to test numbers I've been given for financing MTM.

I'm trying to mark an M&A financing commitment to market. So I went into Cap IQ and pulled fixed income stats on comparable issuances (issuing co has similar Leverage/EBITDA mult, industry, debt maturity, etc…). Now I have a bunch of stat from Cap IQ and I'm trying to figure out how I mark-to-market. Is it just:

Gain(Loss) = -([100] - [Market Price]) * [Total Issuance Amount]

That seems too easy, am I missing something?