I think you have King prawns not shrimps at that price. They are a good replacement for Crabs, at times they out fish crab but not often. I purchase shrimps/prawns but typically wait for a special… At times there can be large differences in price between different brands.
Squid is a good generalist bait, most fish would taste it. I prefer to present it in long thin shreds, often fish it on 3 hook flasher rigs. I typically leave the ‘head and tentacles to last or use them for burley .