It is entirely dependant on how your LEA are delivering your connectivity, dedicated leased lines or shared via a single breakout to the internet. Most providers will quote you a dedicated bandwidth speed on a bearer. In this instance 200mb bandwidth on 1gb bearer. These can be increased throughout the life of the contract but doing so will often start a new contract. With regards to your up front costs, i'm going to assume you haven't had a site survey yet? In that case this will be from the telco. Nowadays, if you go for a 3 year contract most telco providers drop the installation to very little, if anything at all. All you are looking at initially, after site survey is excess construction charges, IF any are found.
From Exa's side if you were taking our DarkLight or a EAD based leased line then we can literally flick the switch up at any point with the only additional costs being for the new bandwidth requirement.
Really not sure what the up front at the exchange cost is, but if you want to send me the quote I am happy to take a look and figure out what they are talking about for you.