I have some self employed, rental (and PAYE part time) I do alot of the donkey work, categorise and list in/outs so fairly tidy for accountant and pay £450-550 depending on complexity/advice offered in that tax year - sole trader not limited. So for 2/3 years you should be able to work out a cheaper rate per year - you would save money by not giving them a shoe box full of receipts & invoices and spread sheeting the info.
Be prepared for some questions before they take you on, some practices may say no as they won't want the hassle - be honest and they may take pity, help and solve the problems. Good luck, don't worry it will all get sorted!