Hey, Welcome to the forum..usually low budget and modding don't work but there are a few things you can do here and there to "pimp" your ride.
LOOKS:
1st Gen - Car Care, ... - Acura TSX Club : Acura TSX Forum
Plasti dip grill chrome except for "A", some like chrom some don't
Plasti Dip Door trip or use something called BMW shadow line again you might like the chrome is not then here you go.
De-badge the "TSX" "ACURA" from trunk leave the "A"
Paint Calipers black or red or whatever color you want.
valve cover, engine bay can be painted.
Fog lights they sell a vinyl thats yellow if your into that look.
Performance:
1st Gen - Engine, ... - Acura TSX Club : Acura TSX Forum
1. Throttle body coolant mod (Free) aka TB coolant bypass
http://tsx. a c u r a z i n e .com/forums/showthread.php?t=649712&page=2 (take the spaces off)
or
http://www.tsxclub.com/forums/1st-gen-engine/27465-throttle-body-pass-pics.html
2. DIY Intake many version use the search. That should be pretty cheap. even free
3. you can eliminate the oval resonator on the exhaust, not a noticable thing but drop 2-3 pounds of car that can help. cheap $30
4. Hondata heat Shied Gasket about $50 combines with TB bypass by far one of the best mods.
5.Header - Ebay topspeed is said to be good , weapon R has been proven to have best results comptech is direct fit not as good but still good. (need at least 400)
Suspension:
1. springs or aspec kit
2. TLS Rear sway Bar - 40$ shipped
3. TLS front sway bar - Pain in the ass would not do it again.
keep checking the classifieds there's tons of items for sale that will help you out for cheap
im sure theres more and everyone will chime in, Just use the SEARCH and ask questions after you look it up, chances are its been answered. good luck with your car.
happy modding!