It's called qualifying your prospect. I suspect something you said or did suggested that you were going to be a lot of time for a minimal commission and they didn't want to be bothered with it. Short term and small leases are very uninteresting to brokers as their commission is based on the total lease value.
1) Who are you? Are you going to be around for the long haul, is it temporary, are you likely to be able to pay the bills or are you going to break the lease in six months when the desire arises. When you break the lease, are they going to be able to collect the termination fee, if not, that all gets factored into the price.
2) What are you doing? Is it a data center, are you going to have a lot of foot traffic, are you going to have people living there all the time writing code, requiring them to keep the environmental units on all the time, i.e. do you need to be in a 24x7 office building. In DC and Baltimore where I leased a lot of space over the years, many buildings didn't operate chillers on the weekends and a southern exposure with untinted windows made it unbearable. Even during the week, the A/C units struggled to keep our space cool, but, it was cheap - and now we knew why the law firm didn't have a problem giving up what we considered 'prime space'.
3) What's your budget - do you want scenic views of the Hudson or Central Park, or, are you willing to get space somewhere without a view. Real estate gets more expensive the closer you get to public transportation in NYC and a few other cities. Windows add to it. If you're looking for a space just to get people together on a daily basis and can turn a cave into a workspace, then you can find properties that have been carved out of companies that have downsized where they kept the window, but threw away the rest of the 'useless' space. However, if you want that window view from the 50th floor, it isn't going to be cheap. Most floorplans in cities try to make sure every office has access to the central core (elevator bank) and windows. Space without windows is typically storage. One of the spaces I rented in Baltimore was a 1440 sq ft chunk out of the back of a surveying firm. No windows, crazy hallway cut from their office that wound back to the space, but, again, space they were willing to get rid of and remove from their lease. I did sublease space in DC one time in a building and we brought our own construction crew in, created our own door in the hallway and took a chunk of their space.
Find a broker, tell them that you want x thousand square feet, you want a one year lease with two one year options, you don't need a buildout, you're willing to settle with property without a view and you're willing to do a quick close. Be careful with the lease terms and make sure they specify whether it is net or triple net so you're not surprised with the property tax being added to your rental with the first bill is due.
Every building is different, most have separate owners even if they share the same management company. Almost all properties count common space as shared among the lessees based on a percentage of the square footage you lease. Even different floors in the same building can have different prices. Make sure they tell you what the final price is, in writing, on your lease agreement before you take it to your attorney. Depending on whether they have a concierge or doorman, the level of security in the building, i.e. security guard, access control all contributes to your lease price.
Double check utility cost, high tech companies are sometimes asked to submeter, additional cooling requirements are often factored in. You can ask for a space with a shower, but, absolutely don't tell them people are going to be sleeping there. If they ask, many of the employees ride bikes/rollerblade/etc. Find out if you are required to use their cleaning service (or if it is included).