Meguiars Leather Conditioner is awesome at moisturizing the seats. Smells great too. For the emblem, you can paint, carbon fiber, or Plasti Dip. As far as cool things, there's a thread for mods that cost under $100. I'll try to find and link that.
Are you rocking an LS, LT, SS? As far as your cost, it depends how crazy you get. Minimum is doing your springs and your sway links. Most people do a full swap to FE5 at the same time as springs.
IMO, style is one of the biggest advantages to having a car lower. It just looks right to me. Also, it adds advantages to cornering. With a lower center of gravity, the car is able to take turns quicker and with more control. One thing that is said often on this site is that you can make your car reliable, fast, or cheap but you have to pick two. It's all about the depth of the pockets.
I'm bored, so here are some fun things you can do:
HID projector headlamps
CAI or SRI
LED's in trunk, door/window switches, under the hood, in cup holders, in footwells
LED instrument cluster
LED turn signals
Leather shift knob
Carbon fiber just about anything
Weather Tech floor mats
Put a hot girlfriend/wife at shotgun
"You all know I take great pride in my title as Mr. Positive." My Showoff
Lowering is so worth the money. Have you ever took a corner too fast and felt like you were going to role over? If you read that link above and follow that you will feel a huge difference... Its almost like driving a different car.