mods $ is usually greater then upkeep. atleast that was very true for the talon. i did most of my own work, but nothing major ever went wrong. I can do most basic things, in my talon, i did in order, turbo swap, full exhaust, full suspension, cam lifters, half shaft, and speakers, and then i ended in an engine swap. so i have decent mechanic experiance and my neighbor owns his own repair shop and he usually helps me when im in need. i was thinking the a4, i like both but the s4 is so much hotter