Thanks again to everyone! In case anyone else reads this and is looking for something similar, the Hotel Metropolitan Tokyo Marunouchi looks to be a pretty good value option - it's attached to Tokyo Station (as it is owned by JR and will be convenient for me as I plan on taking a day trip out to Kyoto / Osaka / potentially Kobe), has nice looking if somewhat small rooms (though the price is low enough that you could pay up for a larger one and still come in below the prices of other hotels), and came in under $180 a night for a room with a queen bed (smaller rooms with double beds were ~$150). A bit disappointed that the international chain options are all super pricey, particularly the Marriott ones (with their 2x elite nights + 1k bonus pts / night promo), but there's still plenty of reasonably priced options from outside the major international chains.