Squier

What kind of amp are you using?

i want a better sound and all i have is a squier would it be worth putting 3 new single seymour duncan pickups on it or should i just buy a new guitar?

What kind of Squier is it? Do you really like the feel of it, or did you just get it "to learn on"? If you like the feel of it, I say go for it. If you don't think its worth it, save up and buy a MIM Fender, or another guitar. :)

depends on what you want. If you like the feel of the neck and enjoy playing it, a pick up switch could be what you need. However, if youre not too fond of it, you could consider getting a new guitar

i have a Line 6 Spider 2 hawken

What type of sound or tone are you trying to get?

Seeing how you are looking at 3 pickups, it must be a Strat. Well, a Strat sounds like a Strat. They are a great Blues guitar, but you can get heavy with the bridge pickup.

Are you looking for a Metal tone? You could get that by putting a humbucker at the bridge position. You might put a humbucker at the neck as well. This is a very popular configuration.

If you are looking for really heavy tones you might consider a Les Paul or copy like Epiphone. Also a SG or copy is great for this tone.

I am just guessing on all this. You need to tell us what kind of tone you are looking for.

What's your amp and effects loop look like right now?

Putting money into pickups with low end amp and effects isn't going to buy you much in terms of tone.

Lots of questions to ask here before we can say if it's a good idea or not.

What sound do you want to achieve?

What kind of money do you have to spend to achieve that sound?

What's your current sound system look like?

Do you like the guitar?

Etc.