If you really want a spring assisted knife I'd suggest splurging on a Kershaw Leek. That is just a brilliant EDC knife, and it happens to be spring assisted. Historically it was an affordable knife but prices have gotten rather out of control in recent years. Generally the best time to get them is black friday, I think I saw them around $40 this year.

Most (probably all) of the Kershaw Speedsafe models you'll find under $30 are just not worth it. I'm not terribly up on spring assisted knives, but I don't think you're going to find anything worthwhile here.

Now if you're willing to skip assisted opening you'll have the other problem: too many great choices. Here are just a few to look at:

https://www.amazon.com/QSP-Folding-Pocket-handle-Opening/dp/B07V9R56X2

https://www.amazon.com/Firebird-Folding-FB727S-GY-Pocket-Handle/dp/B07X1MVDCZ

https://www.amazon.com/Firebird-Folding-FH41S-GY-Fishing-Hunting/dp/B09JG94KHD