my opinion is totally opposite to yours -
The packets leak when left opened only.they are always primed,juicy and ready to use,95% of the tails work and i wont fish without them,and i dont recall ever seeing a moldy gulp.they are reusable and i have often used 1 packet to catch up to 20 flathead,so as far as value for money goes,i have no problems,i dont remember in my bait days of catching 20 flathead on 1 or 2 packs of prawns,i actually have never caught that many on bait in 1 session,where as i consistently do it with the gulp.