NV is definitely worth it. #hailcaesar

what you should do is don't be impatient. save that wallet money until an annual steam sale(Summer Sale is coming around in June or July). most games would come with a heavy discount. IE you might be able to get the ultimate edition for really cheap.

I'd recommend the ultimate edition with the DLC. They add quite a bit of content and are pretty good, especially Old World Blues. And if you're planning on modding the game, then you'll need the DLC as some mods require them.

Get the full game. New Vegas is a masterpiece and so are the DLCs. Lonesome Road, Blood Money and Old World Blues are some of my favorite DLC of all time.

Get NV and DLC. It's easily the best Fallout Game, with 2 and then 1 behind it. I wouldn't recommend either 3 or 4. Both are pretty mediocre, 4 being the worst.

Personally, I'd go for just the base game. Even though I think that FO:NV is a fantatic game, a lot of people that liked FO3 really didn't like NV. Whats more, I'm Fairly certain that all of the DLC will be discounted next sale. There are a lot of fantastic games on steam at $10 or under even without discounts. The original Deus Ex, one of my favorite games of all time, is $7. F.E.A.R. is $10. The original Fallout is $10. The original Doom and Doom 2 are $5 each. Half-life 1 and 2 are both $10. Magicka is $10. The first Max Payne is $10. I could go on, but I think you get the idea.