Some products may have slightly different pricing between eBay and the standard web shop of Suffolk supplies, and surely there must be a reason for this.
Same applies for certain ranges of soaps, creams, after shaves, etc. which are or not in the eBay store.
However the reason is mainly the selling and pricing strategy of the vendor and not to confuse the buyer, no proprietor would want that.
On eBay, the Connaught shop competes with head on with other eBay vendors, many of which come from Asia, East Europe, etc. and thus have the ability to offer any same product at slightly lower price. This means Connaught may have to adjust for this reason (or for any other reason, this was just an example).
Same applies for some 'seconds' products which occasionally appear on Connaught eBay, while others may be available through a simple announcement via PM by Paul in TSR.
It all relates to the marketing strategy of the particular vendor.