Could be the mfrs. are trying to nudge you away from one part and onto another. It's not uncommon to see prices for "mature" products start to go UP over time (rather than down as you would expect for other goods that age) and replacement products that are better/faster actually cost less. Whenever I see a component price go up I start to smell around for a cheaper replacement.
The UA78M33CKCS is a bit cheaper, for example.
Also PTH parts are falling out of favor so you might have more luck with an SMT version.
The Flexible MIDI Shield
: MIDI IN/OUT, stacking headers, your choice of I/O pins