Purchase priceTransport inwards for $50$ digestersImport duties on $50$ digesters Special one$-$off WWF $($World Wide Fund for Nature$)$ rebate to promote eco$-$friendly bio$-$fuel usageRequired: Q$\mathrm{.}4\mathrm{.}1$Q$\mathrm{.}4\mathrm{.}2$Q$\mathrm{.}4\mathrm{.}3$Calculate the cost price of each digester: Ignore VATIf Precious Earth Traders marks up the digesters at $20\%$ on Selling Price, calculate the selling price, excluding VAT, of one digester.