As someone who wanted to purchase either an HTC Desire or an HTC Legend but on pay as you go I struggled. Very few places do these for sale on pay as you go.
Likewise, the Legend is contract exclusive to vodafone or you can buy it sim free for about £350. This seams like a pretty good deal to me for this handset considering its £350ush new.
Its almost £100 off and its brand new condition. It may be used, but it will be absolutely immaculate and if you are lucky enough to live near a CeX then you can just look before you buy or get it shipped up to your local store.