04 mazda 3 2.0L GS, best HP upgrades
 

Hey guys, new here and just bought an 04, mazda 3 GS, it has 150,000km (93,000m) on it. It is an automatic so I dont know if that limits me in the HP upgrades area but I was wondering what the best performance gain to price ratio parts would be good to put on? Say if im looking to spend around $1000-$2000 to start. Or even if there is a few cheaper/smaller upgrades I can do to get things going?

It does have some take off speed but once you get into second gear it feels like it has no power at all heh..