Sometimes dealers sell used scooters that come in as trade-ins. By stopping in at a branded dealer you get to see several different models and price ranges on new or maybe used if there are any. If you want to buy a 50cc scooter, you'd be looking at any of several brands so that's whose showrooms you go to or call. I can't say if everything I list here is available in Pikesville.
This forum mostly addresses the interests of owners of Metropolitans and Ruckus models. Honda makes 49cc Metropolitans. The newer ones are fuel injected, the older ones are carbureted. These are very traditional looking. they are intended just for a rider, no passengers, and not for highway use. Top speed is barely 40mph and could be less. Learn more about those here:
http://powersports.honda.com/2017/metropolitan.aspxHonda also makes the interesting 49cc, more minimalist bike, the Ruckus. Very sturdy and unique. ruckus owners often like to modify or accessorize their scooters and are a little more high spirited in their riding adventures. Look at those here:
http://powersports.honda.com/2017/ruckus.aspxAfter Honda, you can look at similar powered levels in
Vespa (
http://www.vespa.com/us_EN.html),
Genuine (
http://www.genuinescooters.com/buddy50.html), and
Yamaha (
https://www.yamahamotorsports.com/scoot ... no-classic)
I'd say the best idea is to learn more about each model with the pages above or your own research, and focus on what you'd most likely think you want to buy based on price, features, looks, etc. Consider how you think you will be using the bike--just for fun and local riding, daily transportation to work or school, something you want to work on to enhance its performance and looks, something you want to try but might not keep. Then go visit a dealer and hope to see a couple of used models and look at something new on the floor, too. It's unlikely to be much advertising by any owners for used bikes right now in winter, but as the weather warms next year, you might find some privately selling bikes.
Thinking of them as scooters, not mopeds, is a little wiser as they don't have pedals or actually work like mopeds that you might have experienced on a vacation to Bermuda or similar. Motor vehicle agencies in many, but not all, states consider these types of scooters to be motorcycles. Licensing and insurance regulations vary state to state, so be sure to look into those legalities before making any purchase. You will also need a DOT approved helmet to ride safely. If you have no prior experience with scooters, you might want to try one out or take a lesson or two before buying.
There are probably many posts with added suggstions on this forum so use Search to find advice that can help. Hope you find the perfect two wheeler for yourself. Enjoy the quest. Looking for one is almost as much fun as buying a scooter.