Of course you may have to upgrade in the future, if you have to play lollapalooza, you're not gonna take your 15 watt combo.
At the moment you're like 15, been playing 2 years, if i were you i'd look into one of those marshall valvestate models, they are more money than the 15 watt orange, but they are louder, and the distortion channels are monster gain.
Your aim isn't to buy an amp that'll last you your whole life, just something that'll last at least a few years while you get better and more practiced, then if you start gigging, time to save up for a head.