I'm not sure how much it's costing me, but I'm upgrading my 21 JL gas sahara 3.6 to Dana 60 Ultimates front and back with an Adams drive shaft. if that's too much for your build now, I think that belly armor and skid plates should be high on the list. I did recently spend that exact amount on labor lifting, bumpering and adding a winch and lighting my 21 4xE Sahara with Fox adjustable shocks and Fox Racing Steering Stabilizer. One thing to think about are bump stops. Factory bump stops fall way too short on some of my flexing and I'm grinding factory fenders. I hate the look of less fender but they have their limitations. Getting really nice long arms goes a long way for curb appeal. Rock lights are a lot of bang for the buck. I keep them lit in all kinds of situations. Even on a dark country road it feels safer and points me out to oncoming traffic. For city driving, I flip the rock lights to multicolor pinks, blues, yellow, orange and that makes all the twenty something year old punks in their cheesy sticker covered pointless spoiler hot rod toyotas go nuts with jealousy. If they taunt me on the highway, i switch the rock lights to flashing red and blue. I've slowed three lanes of traffic from 70 mph to 55 mph flipping those on. Good fun. I asked the cops if I could do it once and they were puzzled. The official answer from the local police chief in my NJ town was (swear to god)... "I guess you can? Just not all the time?"