I would just like to say, filing your accounts for a micro-entity is easy IF YOU ARE A SIMPLE BUSINESS.
Do not get put off my accountants talking about XFBML and all manner of other terms.
If you are a Limited business, under 10 employees and under £500,000 income (at time of writing) you can file Micro Accounts AND Company Return and pay your Corp Tax all on the HMRC site in one online form - search for "File your accounts and Company Tax Return" (I cant paste the link here)
As long as you are doing good book-keeping, this is a simple input task. Use a system like Kashflow, Quickbooks, Xero, Sage etc. and you can generate reports which give you the figures to enter.
It takes about an hour to file them on that one site. HMRC then pass the accounts to companies house for you. I've done this myself for the past 2 years and saved around £1500 in accountant fee's.
IF you run a service based business this is very simple accounts. We do web design and we have very basic incomings and outgoings and few overheads. We do not have stock and have very few assets. In these cases an accountant is a cost rarely worth it - unless you get scared of book-keeping.
If you have stock of products, a lot of assets or have to handle payroll - then an accountant would be worth it if it goes beyond what you are comfortable with - in most cases an accountant is a only needed when you hit your depth limit in what you know and what you are having a 'good guess' at - this will only come back to bite you.
The other benefit of an accountant is the tips and advice on Tax and how to best reduce the tax bill (without being immoral/illegal), or how to sell assets and so on.
It does depend on your business and how happy you are with book-keeping. You look like a simple online website taking fee's and advertising, you should be able to book-keep easily enough and file your own.