Hey Chris. i see no one has responded. i am not the best to answer this question, but i will try my best to give you a wishy-washy answer.
there are many folders (i assume by your OP that you mean folders) that will fall in your $140 range. but, is a spyderco PM2 better than a Ontario RAT1? therein lies the rub. it really is up to the user to decide.
i guess my first question would be to determine how you want the knife to deploy. i.e. if you want a flipper, there is no sense considering the thumb stud or spydie-holed openers.
others may suggest to find the steel you are looking for and then only look for knives that have that blade steel.
for me, if we are talking about EDC, the ergonomics do it for me. steel is actually secondary. i want the handle to be comfortable and i want a blade shape for the cutting tasks i most perform. but again, all of it is subjective. what deployment do you like? what steel do you like? what handle is comfortable? and, don't get me started on grinds!

the only way to really know is to experiment a bit.
my advice would be to find a local store or gun (or knife) show that will allow you to handle as many as possible. however, i'm guessing that you are posting because you do not have this option.
so, if that's the case, i guess i would recommend scouring the Exchange here on BF, and if you find a good deal, purchase it and check it out. if you are looking at the popular brand names, then even if you don't like it, you can sell it and not lose too much on the trial period.
i also like to cross-check the knives for sale against "popular internet sites" to view feedback scores. you have to take all of it with a grain of salt, but i can be sure i will not buy a knife that has a 3-star rating from 43 reviews (e.g.).
best of luck to you.
EDIT: looks like others have commented now. that is also good recon. there are many threads like this. be a sponge and spend some time scouring these types of threads. while favorites are subjective, they are favorites for reasons. and certain names pop up more than others.