The BM 710 in D2, middle below, is definitely within your range - as barely is the Rukus 610, top below, and the mini-Rukus 615, bottom below. Those two are S30V bladed - and they were canned last fall. You'll have to look for 'New Old Stock', such as a local pusher here has - ~$160-$170. He even had the Auto mini-Rukus 6150! Not liner locks, but great 'AXIS lock' examples.
A less expensive, if you can still find it, secure liner lock is the Buck 419 Folding Kalinga Pro in S30V. Just out a couple of falls ago, it was dropped by the end of last year. Mine is a handful - and a keeper. It's the middle one below, with a Fixed Blade K-P 408 above it and a Folding Hunter 110 below it - for size comparison.
Speaking of the Buck 110 Folding Hunter, it's a real classic. Of course, that is true whether you get the basic model from WallyWorld for $27 or spend hundreds for a Buck Custom Shop 110 in S30V blade steel with expensive scales and nickel silver bolsters. The LH four below are Buck Custom Shop with the CPM154 version made for Bass Pro and the S30V version made for Cabela's to the right. The latter two are ~$75, while the others varied from $84-$180 several years ago. It is my understanding that the best blade steel now available is S30V.
Check out Buck's Custom Shop on their site. They really are 'custom made', albeit in a reasonable time. Great quality, too.
Stainz