Question on Hafler DH 220 price

I have an opportunity to buy a Hafler DH 220 with a Musical Concepts PA3E upgrade that was done in 2008. The ask is $400. Other than the gray housing (not my first choice in color) that gives me pause, I’d seriously like to give this amp a go with my Magnepan MMGs - it’s clearly a very well-regarded amp and I think it would match well with the MMGs and Rhythmik FG12 I bought here on Audiogon. I’m currently running the MMGs and an MMG-C off an Adcom GFA6000 with the surround channels unused to give it some breathing room, but while the sound is not necessarily unpleasant (it’s detailed, open, and revealing of source limitations) I can’t help but think I can get more out of the MMGs than what I’m getting. The other amp under consideration is a B&K ST 30303 with 300 wpc into 4 ohms. I do not have the ability to A/B these or even hear them.

Any thoughts on the two amps side-by-side? My sense is that the Hafler will win out over the B&K with quality watts over the B&K’s quantity. Is the price of the Hafler at $400 too much?

Thanks.