Selling on a web-site

[#1]

Can someone give me a ball-park figure of the financial charge only for selling a £10 item via a web-site
Using
Paypal,
Sage Pay
And RBS Worldpay
Ignoring volume discounts at present

[#2]

Are there multiple transactions occuring at once or single transactions randomly?
Do you have a business bank account? Last time I checked I need a business bank account to be able to setup an automated payment method using paypal or a worldpay solution.

[#3]

just recently, as part of Paypal security, I had to set up a DD account for Paypal to pay a small amount of money, I am not a business customer, I dont sell by Paypal, Just buy

[#4]

@Keith,
a) yes have a business bank account, currently take cash, credit  card, debit card and cheque
b) there could be multiple transactions for each customer.
Have about a dozen stock lines, average item cost is around £2.50, but items could be bought in multiple packs.
Average spend (based on existing business) estimate to be £10-£15.
To aid costing I need a % unit cost financial overhead, if it is more ontop of CC standard. If Paypal and sagepay overhead cost more than CC.
thanks for replies