Hi Gazza,
I purchased the starter kit, with a few extra's and then gave myself a reasonable monthly budget (wife agreement). It gives you a chance to plan and schedule work, monthly, weekly of course there are a few times when I had to save a few months allowance to purchase expensive items i.e. ETB dials. You save money by looking around on the internet, visit shows to get some decent bargins, reduced VAT, no delivery charge. Please do not under estimate the cost of extra's they soon add up. But then I am in no rush to finish the build, if you want a quick build then I would suggest you save more.
Get yourself a decent donor then you can save and prep the donor parts, over the winter period. What ever your final decision don't give up, spend carefully and plan everything. All the best
Regards
Mark