Well, if there was enough interest, I could have an occasional promotion for a CSL "Group Buy Day" - as mentioned above, whereby one day was set aside for a further discount on purchases - for instance all purchases made during one nominated day - received a further discount.
Since my own discount structure often revolves around my own spend with a particular manufacturer / supplier, these group buys could even by manufacturer based - such as a group buy day for Denon, Constella, Abstract etc

. These would only happen occasionally - rather like the Eay Free listing days

, but would enable prices to be reduced for everybody if orders were placed at the same time.
Whether, a group buy for non DJ related items would work or not depends largely on your committment, and I do have mixed feelings on how well it will work - hence this post. Of course we have to get the attentions of the company in question and ask if they are willing to offer a group discount in the first place. It works on a PC related forum - but then again they have 15,000 members!

.
Certainly DJ related group buys could be implemented in the future - depending on your feedback and the amount of support the idea gets, and the discount everybody gets would go up or down depending on the amount of orders received in that day. If two people order the discount would be small, but if 5 people ordered, a bigger discount would be shared, it's all relative.
Yes, Lamps and consumables could also be considered - although £2.89 for the 300 hour ELC lamp version (in Qty's of 30), is already considered a good price especially as some high street retailers still sell the standard version for £7+!!

So you'd need to get orders between you totalling 1000+ to make any further discount appear and somehow I can't see that happening, at least not yet.