Help buying a tennis racquet

I am located in Toronto and looking to buy a new tennis racquet, but despite spending about an hour researching on the internet, I am totally lost.

I have been playing tennis for the past 10 years or so, but with increasing frequency over the past 3-4 years summers. I guess 12-20 times per summer?
I never took lessons as a kid, so my game is not technically proficient, but I would guess I am a 3.0 or a 3.5 (although I really have no idea).

I have been playing for the past 8 years with an old Head TI radical that was given to me (im guessing the racquet itself is over 10 years old).

I don't have a ton of power, and use spin/control a fair bit - so I think that means I should get a racquet that adds power to my game, right? I'm about 5'7 and 150 pounds if that makes any difference.

As a frugal person, I'm looking to get the most value for purchase. I'd be willing to spend around $200, although if I can get an extremely great racquet for only $100 used, I would be happy with that.

Can anyone shed some advice on racquets they recommend (and the price range) for me, in addition to the best places in Toronto to buy a racquet?

Lastly, can someone speak to buying a used racquet. I've been told that demoing is important, which would make it seem like buying used is a bad option, but if the prices are substantially cheaper, I would be ok with that. Are there any Toronto tennis sites to buy racquets like Torontogolfnuts?

Thanks for your advice and feedback!