Removing the cat changes the back pressure.. Performance will suffer to some degree. Further it is bad for the environment ..tread lightly comes to mind.

 

A magnaflo 49 state cat is reasonably priced. Yes its more that a "test pipe" but overall the performance setback is nil.

https://www.magnaflow.com/products?partNumber=23221

 

Go to a towing auction. There are a lot of scrappers that go to these auctions. Tell them you have a cat you need to replace and ask 20 bux for it. It may not be much but its still something. Who knows, you may find a car worth buying. If the audience are all scrappers, they will generally let a car go for just over scrap value.

That's where I got my 91 XJ for 5 bills - it came with 31" tires and 3" lift.

 

Just replaced my original catalytic converter and there was a huge increase in power and throttle response. It must have been way more clogged than I had thought.