If legal for you to purchase and own (important, these are different distinctions), an automatic knife would be the safest for one handed operation. Anything from the Kershaw Launch line will be bulletproof and have decent steel.

Non-auto non-assisted button locks (the type of knife you asked for) are kind of niche. Kizer makes some decent ones, and Civivi makes the exact razor blade utility knife you’re looking for, but in higher quality and within your budget.

Otherwise I gotta say, if you’re not a current knife enthusiast, look for sales on Benchmade Griptilians (or mini-griptilians). The Axis lock is not exactly a button press but if you want higher quality, it’s a good option.

Bokker makes some knives like that, but I’ve always been partial to flippers like the CRKT M21. Does it need to have an actual button? That might limit your choices a bit.

Always been a fan of butterfly knives.

https://www.bladehq.com/cat--114-Butterfly--2423

If you don’t know how to use one, make sure you put masking tape on the edge until you’re comfortable with it.

You can buy dull trainers too.

https://www.milwaukeetool.com/Products/Hand-Tools/Cutting/Knives-and-Blades/48-22-1990 Milwaukee makes one, in several sizes and blade shapes even.

I bought one to cut down on waste with disposable blades and it works great for tearing up packaging and boxes. The steel is supposedly pretty soft, but it’s also around 20 bucks depending on size and blade shape.

The non assisted opening mechanism is probably my least favorite thing about the knife, if I’m honest, but it’s not horrible or anything.

you can do the same using any knife with a “button lock”.

most popular knife of the last couple of years has a button lock variation and it’s less than a $100 https://www.knivesandtools.com/en/pt/-civivi-elementum-button-lock-c2103d-stonewashed-brown-micarta-pocket-knife.htm