Banking shares, a good time to invest???

Well less than a year ago RBS Groups shares peaked at around 618p a share - yesterday I bought 1500 at 55.8p each (£873), now that the goverment has given them a massive cash injection (by effectively buying the bank), the shares have already increased to 72.5p per share, therefore mine are now worth £1087.5, thats a few hundred quid made overnight. If the shares reach even a third of their previous peak (£2.50ish) I'll have shares worth around £3750 so I will be a happy man. On the flip side of the coin I may be out of pocket £873 plus the £25.75 purchase fee, but its a calculated risk I'm willing to take.