What thor says is generally true, although one place to look is the Swift Folder, since it takes a lot of industry standard parts.
If your Marin is a relatively recent hybrid, it should have a 1-1/8" threadless stem, 130mm or 135mm spaced rear hub, a 68mm BB shell, derailleur gears and V-brakes. All of these will go on the Swift just fine. What you'll need is a Swift frameset (two frame components, fork and seatpost), a 1-1/4" headset, and a 406mm wheelset and tires. If you're really ambitious, you can buy new rims and spokes and lace them to your old hubs. You'll spend well over $600 if you buy those parts new. The stock (Xootr) Swift is $700.
So, if your Marin has significantly nicer components than the stock Swift, it might be worth it. Otherwise, buy the stock Swift and switch over any parts from the Marin you prefer.