I know your budget is a bit limited, but try and think ahead a bit. You may want to join a club, (great fun!) They will almost certainly have bottle, and sell air for a small charge, so you don't need a pump. The Ultra is a great hunting rifle in .22, where shot count doesn't matter so much, but it needs a 230 bar fill in .177, and that's a lot of pumping! You mentioned the power curve, it's not really suitable for HFT, for example.
As suggested, I'd go for a S/H S400.

Gus