Read your condo documents...
The condo Declaration sets the formula for the undivided interest percentage. I have seen this determined by square footage of the units, by equal shares and some states rely on value to determine this percentage. Read your Declaration.
A budget will be set at the annual meetings. You will be responsible for just under 1% of this total. (.909%) This is usually payable monthly to the managing agent. Make sure you see the budget and understand what your monthly fee will be. Also find out if there are any special assessments on the unit you are buying. I am sure HomeGuru will tell you if there is anything specific to PA condo law.
Read your bylaws carefully to make sure you can live with the condo rules. Issues like pets, quiet hours, parking and re-sale restrictions may arise.