Good EVW's don't typically cost five dollars, more like nine. I've seen the junk ones as low as $2.50 in home centers. I buy true Japanese made Ushio ones from Bulbsdirect. com. Six at a time might get me down to seven bucks a bulb. GE no longer makes bulbs; but if you do run into theirs, make sure they're from their actual Commercial branch, US Made, and not their former junk import "Consumer" division. ALL EVW's have dichroic coated reflectors, even the junk ones. Impact is apparently just a marked-up private label for B&H, and not the name of the actual manufacturer; and they're obviously dichroic coated glass just like all the rest.
The better Impact version lists for $17, which isn't too bad if you're ordering other things from B&H at the same time and getting free shipping. And it's nowhere near the obscene 900% markup of the Beseler branded ones (they don't actually make them either).
In terms of fit and burn position, ALL EVW's regardless of brand and quality are designed to fit the same. But .... the cheap ones sometimes have their pins break off or corrode in the socket, potentially leading to a periodic socket replacement too.
