@purehaggis Hello and welcome to the forum!
Best advice is to look to Europe for cheaper silver. There are many dealers but here are a few good ones:
You will pay extra shipping but if there is enough quantity then you will get your cheapest bullion for about £16-£17 per oz (depending on spot).
Also, if you wanted just a few coins I will be placing a "group" order for people like I did recently so you can save lots of individual shipping.