i do combine P&P. (sometimes you may have to pay for each lot singularly if so you will be refunded to the combined price.) i always use royal mail, GB P&P cost ( normal letter £2 for value of lots under £10.)  (2nd class signed £3 for value of lots over £10.)  everywhere else normal (under £10 = £4P&P) (tracked over £10 = £9 P&P) these prices are readily available on royal mails website