From what I understand, shears are preferred to hook knives, and very much preferred to conventional knives for cutting belts and clothes away. It's not a matter of jammed buckles, but getting to the buckle past the victim, airbags, and distorted cabin. It's just faster to cut the strap.

FWIW, I've only heard of two cases of jammed seat belt buckle. The first was a jeep that rolled over while off roading. The weight of the driver (~250 lbs) hanging from the belt was enough to jam the buckle. The second was a recall on a child seat. The various detritus from toddlers and preschoolers were enough to gum up the workings of the buckle.

Getting back to the OP, Opinels, some SAKs if you can find them on sale. Work knives (Stanley, Utica, Ontario, Murphy) can be had pretty cheap.

EDIT: If I had $110, I'd go for a $50 fixie and a $60 MT. Better two decent quality knives, then one really good one and one so-so one.