We are all day action people too and only look for a safe and comfortable place to crash at night (and sometimes midday - though more & more we opt to just rest in the parks to not lose out on the time walking back & forth).
150/night is a rare and excellent price these days in the DLR area. Even for the cheaper motels. That being said, if you book in advance and look for deals, it may be possible. Some of our favorites that can be closer to that price range and are really close to the pedestrian entrance on Harbor are: The Anaheim Hotel, Park Vue Inn & Grand Legacy at the Park. We also will check Fairfield Marriott, Tropicana Inn & Suites, Camelot Inn & Suites but those don’t seem to have had great prices anytime recently. Some that we always consider but haven’t yet tried are Del Sol Inn, the 2 Best Western’s just across the street from the crosswalk. We’ve tried the Castle Inn & Suites once and it was a decent option. I would book it again.
You can also expand your search to hotels in the convention area and can walk to the nearby Toy Story Lot and take the free shuttles to the park from there (they do not care one iota if you actually park there or not). The hotels in this area are generally nicer and so pricier, but you get more bang for your buck in this area. The one we used to stay at frequently was the Sheraton Park (when we had an awesome credit card rewards program for SPG hotels that included this one- we got great rates & used points to upgrade to get their awesome hot bfast included free and/or the club lounge- but I don’t know that we would book their rack rates without the rewards now).