I disagree. Especially because his pay is so low compared to market rates. I managed to interview for with a new company, get an offer at 15% up from my current

I disagree. Especially because his pay is so low compared to market rates. I managed to interview for with a new company, get an offer at 15% up from my current pay, threaten to leave, and get a counter offer from my current company at 5k above my outstanding offer. They are taking huge advantage of you at 45k. They know this. If you have other offers in hand, or even make it known you are looking around, your current company will try to give you incentive to stay (in $$$). If they don't, they probably are not worth staying with anyway.