I think you'll find that the £130 is for a factory refurbed (in other words as good as new) exchange. Should come with all the accessories you'd get in the box with a new one and will probably include a mapping upgrade to the current version. Ring 1st to check that this is the case but I'm pretty sure that's what you'll get. Makes spending the money easier to bear as you wont need to pay for the mapping upgrade and you'll have everything as good as new.
On the other hand you could go for a Zumo and sell the 2720 as spares and repair. If you go this route drop me an email at 'red viffer at bt internet dot com' (no spaces) and I might make you an offer subject to me having a discussion with Garmin UK about a 2nd user doing the above.