start up practice help please

Hi, I have started an accountant practise from home specializing in simple clients with no stock and minimal debtors/creditors...dentists and the media sector. I am hesitant to spend on software straightway unless it is a necessity. I have looked at sage instant compliance but this is 700 for up to 25 clients plus the cost of something like sage50. As my clients are quite simple accounting wise, what are my alternatives? Is it advisable / feasible to do the double entries by hand in excel and then use a companies house template for stats and hmrc software for tax? Will sage or the like save me a lot of time? Ate there cheaper start up options? I've looked around and all well received packages seem to come in at around £700 Any help from your own experience would be massively appreciated Thanks