To give you an idea of price, I have been paying £90/month (incl. VAT) for an all inclusive package for both ltd company and personal accounts which covers everything needed for me e.g. Kashflow subscription for bookkeeping, payroll, accounts, annual return, personal and company tax planning etc along with advice over the phone or email whenever needed.
Paid a little extra to also cover insurance for company/personal tax investigations by HMRC (having done some research, if you are ever chosen for one it can apparently take many hours and rack up huge accountancy fees if you want them to deal with it for you - which I would).
When I originally did some comparing the price seemed to be reasonable, perhaps at the upper end of the scale though.