You don't provide any info about the size, location, budget of the coop, size of the garage, other amenities. Are you saying that the coop has $2mm in reserves? Or is that the value of the assets on the financials? What condition is the building in? Are there major projects needed, such as to repair roofs, brick work?
I don't agree with the other comment that the bike and garage rentals should be increased at the same % as maintenance. It depends on the building, supply and demand of the amenities. Do you have storage available, or laundry facilities? They are also sources of income to the coop.
In our building, we charge $24/yr ($2/mo) for bike storage. The space is not usable for much else and it keeps the bikes out of the hallways and elevators, reducing damage and dirt, and the space has easy access to the service entrance. Storage lockers pay for themselves in about a year, we charge $1.50 per sq. foot, and have access within the building. Are all the garage spaces filled by building occupants, is there a waiting list? If 2 of the board members have spaces, out of maybe 50 spaces, 48 others are benefiting too. Are there any costs associated with maintaining the garage?
Cutting the budget is not an easy task. Most of the budget goes to water and sewer charges, property taxes, staff salaries and benefits, building underlying mortgage, professional fees/management, repairs and those necessary utilities - gas/electric/oil/heat/hot water. Most budgets have very little discretionary spending.