Paint is, well, paint. You get what you pay for and everyone that shoots a certain paint will tell you that theirs is the best (that's Valken Redemption Pro from Just Paintball IMO BTW best paint I've shot since I came back to the sport, before that it was Forest Trakka #transparency)
Balance the cost against what you use it for and also which marker you're shooting. Harder shooting markers need a tougher paint to avoid acting like a blender, softer shooting markers can use pretty much anything depending on conditions but you may end up getting a ton of bouncers that will annoy the hell out of you if you go cheaper and harder shell wise.
IMO picking the best paint for your marker and the conditions followed by bore matching are the most important things to consider, assuming that you're purchasing paint that's treated well and rotated, that's also important. Fills can settle if they're left for ages without being used and then they go anywhere but where you were aiming and then you've poured your $$ down the drain so to speak.
TL: DR it's complicated and has a lot of variables, find the best for you