Wheel spacers
 

I want wider tires on my jk Sahara but don’t want to spend the money on new rims are wheel spacers a good idea or should I just fork out the money on new rims?

There's nothing wrong with adapters, which is what almost everyone refers to as "spacers" but are technically different than spacers. Stick with a decent hub-centric one. If you do much work on the jeep yourself, it does get a little aggravating having another set of lugnuts to deal with anytime a brake rotor comes off, but they're a viable option to get more use out of your current wheels. If you are wheelin' hard at all, it's worth just getting a wheel with proper BS.

would new rims and tires cost quite a bit more?

You're going to have to price out what you want and see. Generally speaking no, adapters/spacers are going to be a lot less money

I personly took my spacers off, I noticed a slight difference in how the Jeep handled but in the end, a different set of tires had the same/similar effect later on. I'm must not a fan of spacers, it's another part to worry about, it changes the geometry of the axle (same with running a wheel that isn't "factory spec"), and I'd rather deal with a little rubbing if need be.

do you keep stock size tires and rims? What size tires and rims do you run?

Factory wheels and 35/10.50/R17 on a 2012 Rubicon Unlimited

do you have any rubbing without spacers

No, check my build thread in my signature for more info.