Desktop. Seriously unless you absolutely have to have the portability, a desktop is a better choice. Its upgradable, quieter, runs cooler and will almost always be more powerful at any given price point.
Otherwise at 700 bucks youll probably have to look at an Acer or maybe a MSI if they are on sale. Another place that might be worth checking would be the used market, you could probably get a 3 or 4 year old laptop that has a RTX 20** in it.
I agree with richie.. a desktop is the ultimate choice for gaming.
However, to answer your question directly. I would look through classifieds or any apps people sell secondhand stuff on like FB Marketplace or something. You can usually find where people are trying to sell something quick for whatever reason and be more willing to accept a lower cost of desperation.
In that case I would start with secondhand markets like FB Marketplace to search for deals on gaming laptops, or if you want something new from retail save as much as you can before november when black friday / cyber monday come rolling around. Also prime day on amazon is another good day when they have really good deals on nice gear. My brother bought a Razer Blade laptop almost 300 or 400 off last prime day.