HydroJunkie has made some good points.
One thing you might want to do to get up to speed on the hobby is read the Servo Magazine article here:ntxbg.org/articles/servo20051rcmw.pdf
You might also wan to see the short video here: firstname.lastname@example.org
You are making some presumptions that may or may not have validity - like that "used ships are cheaper." A used ship has had the captain take the time and evffort and expense to build it - they do not come from a factory (as yet).
You may find they are illegal or need to meet specific restrictions to be legal. England and Scotland have, I believe, some pretty strict firearms laws. RC combat ships were illegal in Australia until they got a waiver (they fit under the classification of concealed weapons, like handguns) until they got a waiver. And they still cannot use BB caliber and have strict maximum velocity restrictions, I believe. And, it appears they are classified as firearms in New Jersey. You do need to investigate local firearms laws.
As noted by Hydrojunkie, the first
thing to do is find the closest local club, or some nearby captains. You can learn a lot by going to an event or two, including local battles (you just missed the North American Big Gun Open near Dallas, MWC Nats in Houston, and IRCWCC Nats). Your local club may even have a club or lender ship - or it may not. But they can give you advice and help, and may be a source of used ships, if one comes available.
I hope that helps. Welcome to the fray.