There's only one way to update a garmin satnav without risking destroying it. You can find details of how to do so at http://www.fixya.com/support/r5628920-update_garmin_satnav_maps
. To do a once off update will cost in the region of 80 euros. To get a lifetime update will cost around 140 euros. The price varies depending on the map you want to download. This is for the lifetime of the satnav rather than your lifetime.
The nuvi 200 is a discontinued satnav, even though it may only be a few years old, and the problem with it is that it probably won't be able to hold the complete updated map. This means that you'll have to download only part of the map e.g. if you have a map of Europe you may have to settle for Western Europe or Central Europe etc. You can download the whole map to your computer and install the remainder to an SD card. However maps on an SD card rarely work with the nuvi 200.
So it depends on what you want. If you want the complete map it may be better to go for a new satnav and try to sell your old one to cover part of the cost. If you only use the satnav in your own country or state you might be happier to just update and settle for part of the map. Some new garmin satnavs come with free lifetime map updates. They can be identified by the letters LMT at the end of the model name. Of course you're paying for them in the price of the satnav. The problem with the new satnavs is that in 3 years time or so they will also be discontinued and outdated and the full maps will probably not fit on them either.