You say that "Our maintenance income does not meet our operating expenses," which is certainly a problem. The money's got to come from somewhere; depleting your reserve fund to pay day-to-day expenses is intrinsically a bad idea. You're just putting off the day when you'll have to raise maintenance -- and probably by a lot.

As for your reserve fund itself, the rule I've heard is that your reserve should contain at least three months' worth of maintenance. Lawyers performing due diligence for potential buyers are going to get nervous if the reserve fund is lower than that. "Far less than $100K" sounds like way too little for a 120-unit building.

It can be difficult to overcome resistance -- both within the Board and among shareholders -- but a straightforward, transparent approach is usually best. "We're spending $X per year, and we're not wasting any of it on unnecessary luxuries, so it's a matter of simple arithmetic that maintenance needs to be $Y per share to balance our budget." Especially given the current credit crisis, people should readily understand that careful money management is essential.