Your work won't reimburse your hotel??

Per the T&Cs: A member may purchase or receive as a gift a combined maximum of 50,000 points per calendar year.
So you're limited to a week of points for purchase, unless you catch a promo as you said. Those 50k points will cost $625. Opportunity cost is the $625 + the estimated 30k points in earning you mentioned so don't forget to factor that, since that is several nights worth of 'lost' points earn.

Can't predict when/if the next point buy promo will come up unfortunately. As you mentioned, only other option is converting points since that doesn't count to the above 50k buy/gift limit.