I have a Cessna 150 that's minimally equipped. The radio rack is original from 1975 except that the sole NAV/COMM has been replaced by an MX300. It also has an ADF, and, strangely, marker beacons but no glideslope. Also has a 4-pound paperweight aka LORAN. I would like to add enough equipment for basic IFR and to train instrument students. At a minimum for IFR training, I would need to add a glideslope receiver and indicator. Preferably, I would also want to add a second NAV/COMM or just a NAV, and/or a DME, or a GPS that can at least be used in lieu of DME to identify fixes--I don't necessarily need GPS approach capability. I have come up with a very interesting option which is to add a KNS-80 VOR/DME RNAV. Not because I actually want an RNAV, but because I would get a second VOR/LOC receiver, a glideslope, and a DME transceiver all in one box. I can probably get the KNS-80 and an indicator to go with it for ~$1,000. I know it's a large box but my panel appears to have the space--unless there's not enough depth. Am I crazy? On the other hand, I am less concerned about spending money than I am about negative ROI (I wouldn't mind spending $ if it increases the value of the airplane).