Is it worth rebuilding a old dream bike of mine?

I got offered a 2004 Ktm 250sx for $600 that’s registered, to some it’s just a old bike but this was one of my dreams bikes to build when I go into the hobby back in 2017-2018 watching a YouTuber. I’m kinda having a hard time on deciding what I should do with the bike, should I build it how I want and even if I wanted to sell it I can make small amount of profit or break even. Or get it all running again have a fun and sell it to make an easy 2k profit. I also kinda enjoy the idea of trail/enduro riding as I’ve never really experienced it before so building the bike for that would be interesting