I would be most pissed off if i was selling someting for £10, making £5 profit, and my supplier selling for £5, making say £2 profit (the profit of which is irrelevant), especially when I have also paid the same £5.

What then is the point of traders buying from the supplier when the supplier is selling for the same price and then loosing the sale?

Basically Phil, you're left with 3 sensible options.

1> Sell to both trade and retail, but dont under cut your re-sellers
2> Sell only to Public or Trade. If trade only, and you received a retail query, point them to your nearest outlet.
3> Sell to both trade and retail, but have a proper pricing structure. You could either match prices with your sellers, or sell a bit more expensive. This is difficult to regulate, as you cannot force traders to sell at your price, and you'll always get a trader or 2 who sells alot cheaper than someone else, and therefore get the occasional grievence.

Personally, as you appear to do little retail sales, and more trade, then i'd stick with your trade and knock retail on the head. Therefore, picking option 2. No one is having to pay anymore for your goods, you're not loosing out on any money, as the trader will always want to replenish sold stock and then everyone is happy.

If i'm talking complete bollocks, please let me know